RESUMO
BACKGROUND: This study aimed to investigate the differentiation of ameloblastic-like cells and the nature of the secreted eosinophilic materials in adenomatoid odontogenic tumors. METHODS: We studied histological and immunohistochemical characteristics of 20 cases using: cytokeratins 14 and 19, amelogenin, collagen I, laminin, vimentin, and CD34. RESULTS: Rosette cells differentiated into ameloblastic-like cells positioned face-to-face, displaying collagen I-positive material between them. Epithelial cells of the rosettes can differentiate into ameloblastic-like cells. This phenomenon probably occurs due to an induction phenomenon between these cells. The secretion of collagen I is probably a brief event. Amelogenin-positive areas were interspersed by epithelial cells in the lace-like areas, outside the rosettes and distant from the ameloblastic-like cells. CONCLUSIONS: There are at least two types of eosinophilic material in different areas within the tumor, one in the rosette and solid areas and another in lace-like areas. The secreted eosinophilic material in the rosettes and solid areas is probably a product of well-differentiated ameloblastic-like cells. It is positive for collagen I and negative for amelogenin, whereas some eosinophilic materials in the lace-like areas are positive for amelogenin. We hypothesize that the latter eosinophilic material could be a product of odontogenic cuboidal epithelial or intermediate stratum-like epithelial cells.
Assuntos
Ameloblastoma , Proteínas do Esmalte Dentário , Tumores Odontogênicos , Humanos , Amelogenina , Tumores Odontogênicos/patologia , Imuno-Histoquímica , Ameloblastoma/patologia , Células Epiteliais/patologia , Colágeno , Diferenciação CelularRESUMO
BACKGROUND/PURPOSE: There are few studies comparing the expression of enamel proteins, such as amelogenin, and cytokeratins in cyst and odontogenic tumors like in ameloblastoma and odontogenic keratocyst, indicating that amelogenin could be a potential biomarker for the aggressiveness in the odontogenic tumors. The aim of this study was to evaluate if the expression of amelogenin, cytokeratin AE1/AE3 (CKAE1/AE3) and cytokeratin 14 (CK14) in cysts and odontogenic tumors with calcified matrices such as calcifying odontogenic cyst (COC), compound (CdO) and complex (CxO) odontomas, adenomatoid odontogenic tumor (AOT) and calcifying epithelial odontogenic tumor (CEOT) as an aggressiveness indicator. MATERIALS AND METHODS: Three COC, eight CxO, three CdO, twelve AOT, two CEOT and three dental germs were submitted to an immunohistochemistry panel of antibodies composed of amelogenin, CKAE1/AE3 and CK14. RESULTS: CKAE1/AE3 and CK14 was present in all odontogenic epithelia. The amelogenin protein was detected in prismatic and amorphous calcified matrices of epithelial origin belonging to CxO, CdO, AOT, COC and the tooth germs used as controls. On the other hand, the CEOT was the only tumor or cyst studied that did not present immunostaining for amelogenin in calcified matrices. CONCLUSION: Amelogenin was detected in pathologies with a low or absent recurrence rate and excellent prognosis. CEOT was the lesion of greater clinical aggressiveness which did not express amelogenin. The presence of amelogenin in calcified matrices of odontogenic arise could be an indicator of low aggressiveness.
RESUMO
Male-to-female sex reversal in horses is a developmental disorder in which phenotypic females have a male genetic constitution. Male-to-female sex reversal is the second most common genetic sex abnormality, after X chromosome monosomy. All male-to-female sex reversal cases studied to date have been found to be infertile. Therefore, a screening test is particularly useful in laboratories doing DNA genotyping in horses. Our laboratory has tested > 209,000 horses for parentage using a panel of microsatellite markers and the sex marker gene amelogenin (AMEL). Suspect XY sex reversal cases are reported females with a male profile by AMEL testing. After routine genotyping, 49 cases were detected and further tested using the sex-determining region Y (SRY) gene, confirming the XY SRY-negative genotype of suspect sex reversal cases. When some inconsistencies arose in the initial result, a molecular panel of X- and Y-linked markers was analyzed for these samples. Of the 49 cases, 33 were confirmed as XY SRY-negative. The remaining 16 cases were identified as false-positives as a result of anomalies of AMEL testing in horses.
Assuntos
Transtornos do Desenvolvimento Sexual/veterinária , Técnicas de Genotipagem/veterinária , Doenças dos Cavalos/diagnóstico , Fatores de Transcrição SOX/genética , Amelogenina/genética , Animais , DNA/genética , Transtornos do Desenvolvimento Sexual/diagnóstico , Transtornos do Desenvolvimento Sexual/genética , Feminino , Genótipo , Técnicas de Genotipagem/normas , Doenças dos Cavalos/genética , Cavalos , MasculinoAssuntos
Aedes , Aedes/genética , Amelogenina/genética , Animais , DNA/genética , Comportamento Alimentar , Feminino , Genes sry , Humanos , Masculino , RefeiçõesRESUMO
Amelogenin isoforms, including full-length amelogenin (AMEL) and leucine-rich amelogenin peptide (LRAP), are major components of the enamel matrix, and are considered as signaling molecules in epithelial-mesenchymal interactions regulating tooth development and periodontal regeneration. Nevertheless, the molecular mechanisms involved are still poorly understood. The aim of the present study was to identify novel binding partners for amelogenin isoforms in the cementoblast (OCCM-30), using an affinity purification assay (GST pull-down) followed by mass spectrometry and immunoblotting. Protein-protein interaction analysis for AMEL and LRAP evidenced the plasminogen activation system (PAS) as a potential player regulating OCCM-30 response to amelogenin isoforms. For functional assays, PAS was either activated (plasmin) or inhibited (ε-aminocaproic acid [aminocaproic]) in OCCM-30 cells and the cell morphology, mineral nodule formation, and gene expression were assessed. PAS inhibition (EACA 100 mM) dramatically decreased mineral nodule formation and expression of OCCM-30 differentiation markers, including osteocalcin (Bglap), bone sialoprotein (Ibsp), osteopontin (Spp1), tissue-nonspecific alkaline phosphatase (Alpl) and collagen type I (Col1a1), and had no effect on runt-related transcription factor 2 (Runx2) and Osterix (Osx) mRNA levels. PAS activation (plasmin 5 µg/µl) significantly increased Col1a1 and decreased Bglap mRNA levels (p < .05). Together, our findings shed new light on the potential role of plasminogen signaling pathway in the control of the amelogenin isoform-mediated response in cementoblasts and provide new insights into the development of targeted therapies.
Assuntos
Amelogenina/metabolismo , Diferenciação Celular , Cementogênese , Cemento Dentário/metabolismo , Proteínas do Esmalte Dentário/metabolismo , Plasminogênio/metabolismo , Amelogenina/genética , Animais , Linhagem Celular , Ativação Enzimática , Regulação da Expressão Gênica , Redes Reguladoras de Genes , Camundongos , Ligação Proteica , Mapas de Interação de Proteínas , Transdução de SinaisRESUMO
In most cases, male sexual differentiation occurs with SRY gene mediation. However, exceptional genotypes have been identified, as shown in this paper. This was a male adult patient seen at the Servicio de Paternidades, Instituto de Genética, Universidad Nacional de Colombia. The following procedures were carried out: Amelogenin gene and short tandem repeat analyses using human identification commercial kits, conventional karyotype, SRY fluorescent in situ hybridization, PCR analysis for Y chromosome microdeletions, clinical evaluation, and genetic counseling. We present an adult male with unambiguous genitalia, karyotype 46,XX, and an SRY negative and ZFY positive molecular profile. The diagnosis of nonsyndromic 46,XX testicular disorder of sex development (DSD) -a rare genetic condition- was established. Only 20 % of similarly diagnosed patients are SRY negative and exhibit diverse molecular profiles. Until now, available evidence seems to indicate that, even in the absence of SRY, the ZFY factor is involved in male sexual differentiation.
En la mayoría de los casos, la diferenciación sexual masculina ocurre con la participación del gen SRY. Sin embargo, se pueden presentar otros genotipos excepcionales, como en el caso que se presenta en este reporte. Se trata de un paciente adulto de sexo masculino atendido en el Servicio de Paternidades del Instituto de Genética de la Universidad Nacional de Colombia. Se le hicieron los análisis del gen de la amelogenina y de repeticiones cortas en tándem (Short Tandem Repeat, STR) específicas para el gen SRY con estuches comerciales de identificación humana, así como los de cariotipo convencional e hibridación in situ fluorescente del SRY, y el estudio de microdeleciones del cromosoma Y mediante reacción en cadena de la polimerasa (PCR). Se le hizo la evaluación clínica y se le brindó asesoramiento genético. El paciente no presentaba ambigüedad genital, su cariotipo era 46 XX, y el perfil molecular era negativo para el gen SRY y positivo para el ZFY. Se le diagnosticó un trastorno de diferenciación sexual 46 XX testicular no sindrómico, una rara condición genética. Solo el 20 % de los pacientes con este diagnóstico son negativos para SRY y exhiben perfiles moleculares diversos. La información disponible parece indicar que el ZFY está relacionado con la diferenciación sexual masculina, aún en ausencia del gen SRY.
Assuntos
Transtornos 46, XX do Desenvolvimento Sexual/diagnóstico , Transtornos 46, XX do Desenvolvimento Sexual/genética , Genes sry , Genitália Masculina/anatomia & histologia , Adulto , Amelogenina/análise , Deleção Cromossômica , Cromossomos Humanos Y/genética , Eletroforese Capilar , Genótipo , Humanos , Hibridização in Situ Fluorescente , Infertilidade Masculina/diagnóstico , Infertilidade Masculina/genética , Cariotipagem , Fatores de Transcrição Kruppel-Like/análise , Fatores de Transcrição Kruppel-Like/genética , Masculino , Repetições de Microssatélites , Técnicas de Amplificação de Ácido Nucleico , Linhagem , Reação em Cadeia da Polimerase/métodos , Aberrações dos Cromossomos Sexuais , Transtornos do Cromossomo Sexual no Desenvolvimento Sexual/diagnóstico , Transtornos do Cromossomo Sexual no Desenvolvimento Sexual/genéticaRESUMO
En la mayoría de los casos, la diferenciación sexual masculina ocurre con la participación del gen SRY. Sin embargo, se pueden presentar otros genotipos excepcionales, como en el caso que se presenta en este reporte. Se trata de un paciente adulto de sexo masculino atendido en el Servicio de Paternidades del Instituto de Genética de la Universidad Nacional de Colombia. Se le hicieron los análisis del gen de la amelogenina y de repeticiones cortas en tándem (Short Tandem Repeat, STR) específicas para el gen SRY con estuches comerciales de identificación humana, así como los de cariotipo convencional e hibridación in situ fluorescente del SRY, y el estudio de microdeleciones del cromosoma Y mediante reacción en cadena de la polimerasa (PCR). Se le hizo la evaluación clínica y se le brindó asesoramiento genético. El paciente no presentaba ambigüedad genital, su cariotipo era 46 XX, y el perfil molecular era negativo para el gen SRY y positivo para el ZFY. Se le diagnosticó un trastorno de diferenciación sexual 46 XX testicular no sindrómico, una rara condición genética. Solo el 20 % de los pacientes con este diagnóstico son negativos para SRY y exhiben perfiles moleculares diversos. La información disponible parece indicar que el ZFY está relacionado con la diferenciación sexual masculina, aún en ausencia del gen SRY.
In most cases, male sexual differentiation occurs with SRY gene mediation. However, exceptional genotypes have been identified, as shown in this paper. This was a male adult patient seen at the Servicio de Paternidades, Instituto de Genética, Universidad Nacional de Colombia. The following procedures were carried out: Amelogenin gene and short tandem repeat analyses using human identification commercial kits, conventional karyotype, SRY fluorescent in situ hybridization, PCR analysis for Y chromosome microdeletions, clinical evaluation, and genetic counseling. We present an adult male with unambiguous genitalia, karyotype 46,XX, and an SRY negative and ZFY positive molecular profile. The diagnosis of nonsyndromic 46,XX testicular disorder of sex development (DSD) -a rare genetic condition- was established. Only 20 % of similarly diagnosed patients are SRY negative and exhibit diverse molecular profiles. Until now, available evidence seems to indicate that, even in the absence of SRY, the ZFY factor is involved in male sexual differentiation.
Assuntos
Transtornos do Desenvolvimento Sexual , Transtornos Testiculares 46, XX do Desenvolvimento Sexual , Diferenciação Sexual , Sequências de Repetição em Tandem , Genes sry , AmelogeninaRESUMO
Amelogenin is one of the enamel matrices secreted by ameloblasts. A mutation of the amelogenin gene can cause hereditary dental enamel defects known as amelogenesis imperfecta (AI). Since lysosome-associated membrane protein-1 (LAMP-1), -3 (LAMP-3), and 78kDa glucose-related protein (Grp78) were identified as binding proteins of amelogenin, several studies have suggested the involvement of these binding proteins with the cell kinetics of ameloblasts in normal or abnormal conditions. The purpose of this study is to investigate the distribution of these amelogenin binding proteins in the ameloblast cell differentiation of mice with a point mutation of the amelogenin gene (Amelx*). The incisors of Amelx* mice had a white opaque color and the tooth surface was observed to be rough under a scanning electron microscope. Among the sequential ameloblast cell differentiation in the Amelx* mice, the shape of ameloblasts at the transition stage was irregular in comparison to those in wild-type (WT) mice. Immunostaining of Grp78 revealed that the whole cytoplasm of the transition stage ameloblasts was immunopositive for Grp78 antibody, while only the distal part of cell was positive in the WT mice. Furthermore, in the Amelx* mice, the cytoplasm of the transition stage ameloblasts was immunopositive for LAMP-1 and LAMP-3. These results suggest that Amelx* may cause the abnormal distribution of amelogenin binding proteins in the cytoplasm of ameloblasts.
La amelogenina es una de las matrices de esmalte secretadas por los ameloblastos. Una mutación del gen de amelogenina puede causar defectos hereditarios del esmalte dental conocidos como amelogénesis imperfecta (AI). Dado que la proteína de membrana asociada a lisosoma-1 (LAMP-1), -3 (LAMP-3) y la proteína relacionada con la glucosa de 78 kDa (Grp78) se identificaron como proteína de unión a amelogenina, varios estudios han sugerido la participación de estas proteínas con la cinética celular de los ameloblastos en condiciones normales o anormales. El objetivo del estudio fue investigar la distribución de LAMP-1, LAM-3 y Grp78 durante la diferenciación celular de ameloblastos de ratones con una mutación puntual del gen de amelogenina (Amelx*). Los incisivos de los ratones Amelx* presentaron un color blanco opaco y se observó en microscopio electrónico de barrido que la superficie del diente era áspera. La diferenciación celular secuencial y la forma de los ameloblastos en la etapa de transición en los ratones Amelx* fue irregular en comparación con los ratones silvestres (RS). La inmunotinción de Grp78 reveló que todo el citoplasma de los ameloblastos en etapa de transición fue inmunopositivo para el anticuerpo Grp78, mientras que solo la parte distal de la célula fue positiva en los ratones RS. Además, en ratones Amelx*, el citoplasma de los ameloblastos en etapa de transición fue inmunopositivo para LAMP-1 y LAMP-3. Estos resultados sugieren que Amelx* puede causar distribución anormal de proteínas de unión a amelogenina en el citoplasma de los ameloblastos.
Assuntos
Animais , Camundongos , Proteínas de Membrana Lisossomal/metabolismo , Amelogenina/metabolismo , Amelogênese Imperfeita , Proteínas de Choque Térmico/metabolismo , Microscopia Eletrônica de Varredura , Imunofluorescência , Esmalte Dentário/patologia , Proteína 1 de Membrana Associada ao Lisossomo/metabolismo , Amelogenina/genética , Proteína 3 de Membrana Associada ao Lisossomo/metabolismo , Incisivo/patologiaRESUMO
OBJECTIVES: This study aimed to revisit benign odontogenic ghost cell lesions (BOGCL) by hematoxylin and eosin staining and immunohistochemistry. MATERIALS AND METHODS: Thirty cases of calcifying odontogenic cyst (COC) and 6 cases of dentinogenic ghost cell tumor (DGCT) were selected for histopathological and immunohistochemical analysis. Sections stained for cytokeratin (K) 14, K-19, amelogenin, collagen type 1 (COL-1), and dentin matrix acidic phosphoprotein 1 (DMP-1) were evaluated using qualitative analysis. Sections stained for Ki-67 and minichromosome maintenance protein-2 (MCM-2) were evaluated using semi-quantitative analysis. RESULTS: A morphologic overlap was noticed in all BOGCL. Moreover, no differences were detected in the expression of K-14 and K-19. The expression of proliferative markers Ki-67 and MCM-2 was similar between cystic and tumor lesions (p > .05). The presence of COL-1 and absence of amelogenin in the so-called dysplastic dentin, associated with its histologic pattern, suggest that this is in fact an enameloid-like tissue. CONCLUSIONS: The dysplastic dentin should be considered an enameloid-like tissue in these lesions. CLINICAL RELEVANCE: The similarity in histology, protein expression, and proliferative marker indices between COC and DGCT suggest that they are a sole entity and likely represent types of the same neoplasia.
Assuntos
Dentina , Cisto Odontogênico Calcificante , Tumores Odontogênicos , Colágeno Tipo I , Humanos , QueratinasRESUMO
Amelogenesis imperfecta is a group of developmental disorders of the dental enamel that is mainly associated with mutations in the AMELX gene. Clinically, it presents different phenotypes that affect the structure and function of dental enamel both in primary and secondary dentition. The purpose of this study was to conduct a literature review on the AMELX functions and mutations that are related to amelogenesis imperfecta. A literature search was carried out in two databases: PubMed and Web of Science, using the keywords "AMELX", "amelogenin", "amelogenesis imperfecta" and "AMELX mutation". Forty articles were reviewed, with AMELX being found to be the predominant gene in the development of dental enamel and amelogenesis imperfecta by altering the structure of amelogenin. In the past few years, the characteristics of the amelogenesis imperfecta process have been described with different phenotypes of hypoplastic or hypo-mineralized enamel, and different mutations have been reported, by means of which the gene sequencing and the position of mutations have been determined.
La amelogénesis imperfecta es un grupo de trastornos de desarrollo del esmalte dental asociados principalmente con mutaciones en el gen AMELX. Clínicamente presenta diferentes fenotipos que afectan la estructura y función del esmalte, tanto de la dentición primaria como secundaria. El objetivo de este estudio fue realizar una revisión bibliográfica de las funciones y mutaciones de AMELX relacionadas con amelogénesis imperfecta. Se llevó a cabo una revisión bibliográfica en dos bases de datos: PubMed y Web of Science, usando las palabras clave "AMELX", "amelogenina", "amelogénesis imperfecta" y "mutación de AMELX". Fueron revisados 40 artículos y se encontró que AMELX es el gen predominante en el desarrollo del esmalte dental y de la amelogénesis imperfecta, alterando la estructura de la amelogenina. En los últimos años se han descrito las características en el proceso de amelogénesis imperfecta con diferentes fenotipos de esmalte hipoplásico o hipomineralizado y se han reportado diferentes mutaciones, con lo que se ha determinado la secuenciación del gen y las posiciones de las mutaciones.
Assuntos
Amelogênese Imperfeita/genética , Amelogenina/genética , Esmalte Dentário/patologia , Amelogênese Imperfeita/patologia , Humanos , Mutação , FenótipoRESUMO
Resumen La amelogénesis imperfecta es un grupo de trastornos de desarrollo del esmalte dental asociados principalmente con mutaciones en el gen AMELX. Clínicamente presenta diferentes fenotipos que afectan la estructura y función del esmalte, tanto de la dentición primaria como secundaria. El objetivo de este estudio fue realizar una revisión bibliográfica de las funciones y mutaciones de AMELX relacionadas con amelogénesis imperfecta. Se llevó a cabo una revisión bibliográfica en dos bases de datos: PubMed y Web of Science, usando las palabras clave AMELX, amelogenina, amelogénesis imperfecta y mutación de AMELX. Fueron revisados 40 artículos y se encontró que AMELX es el gen predominante en el desarrollo del esmalte dental y de la amelogénesis imperfecta, alterando la estructura de la amelogenina. En los últimos años se han descrito las características en el proceso de amelogénesis imperfecta con diferentes fenotipos de esmalte hipoplásico o hipomineralizado y se han reportado diferentes mutaciones, con lo que se ha determinado la secuenciación del gen y las posiciones de las mutaciones.
Abstract Amelogenesis imperfecta is a group of developmental disorders of the dental enamel that is mainly associated with mutations in the AMELX gene. Clinically, it presents different phenotypes that affect the structure and function of dental enamel both in primary and secondary dentition. The purpose of this study was to conduct a literature review on the AMELX functions and mutations that are related to amelogenesis imperfecta. A literature search was carried out in two databases: PubMed and Web of Science, using the keywords AMELX, amelogenin, amelogenesis imperfecta and AMELX mutation. Forty articles were reviewed, with AMELX being found to be the predominant gene in the development of dental enamel and amelogenesis imperfecta by altering the structure of amelogenin. In the past few years, the characteristics of the amelogenesis imperfecta process have been described with different phenotypes of hypoplastic or hypo-mineralized enamel, and different mutations have been reported, by means of which the gene sequencing and the position of mutations have been determined.
Assuntos
Humanos , Esmalte Dentário/patologia , Amelogenina/genética , Amelogênese Imperfeita/genética , Fenótipo , Amelogênese Imperfeita/patologia , MutaçãoRESUMO
Resumen Introducción. El ADN antiguo que se extrae de los restos óseos humanos permite analizar la composición genética de las poblaciones precolombinas y determinar las dinámicas poblacionales que dieron origen a la diversidad de las poblaciones contemporáneas. Objetivo. Determinar la diversidad genética y la relación con otras comunidades contemporáneas y antiguas de América, de los restos óseos asociados al Templo del Sol en Sogamoso, Colombia. Materiales y métodos. Se analizaron 13 individuos pertenecientes al periodo precolombino muisca (siglos IX-XVI d. C.), provenientes de los alrededores del Templo del Sol en Sogamoso, Boyacá, Andes orientales colombianos. Se amplificó el ADN mitocondrial (ADNmt) y se determinaron los polimorfismos de la longitud de los fragmentos de restricción (Restriction Fragment Length Polymorphism, RFLP) para los cuatro haplogrupos amerindios (A, B, C y D). Además, se amplificaron y analizaron los marcadores autosómicos, incluida la amelogenina, y los marcadores de los polimorfismos de repeticiones cortas en tándem (Short Tandem Repeat, STR) del cromosoma Y. Resultados. El haplogrupo A fue el linaje mitocondrial más frecuente en esta población, seguido de los haplogrupos B y C; no se detectó el haplogrupo D. Los análisis de variación genética indicaron una diversidad semejante a la de las poblaciones pertenecientes a la familia lingüística chibcha, contemporánea en Colombia y Centroamérica. Se logró hacer la determinación molecular del sexo de los individuos estudiados y compararla con los datos osteológicos. Con una sola excepción, los datos bioantropológicos y moleculares concordaron. Conclusiones. Estos resultados aportan nuevos elementos a la hipótesis del origen centroamericano de los grupos chibchas del altiplano cundiboyacense con base en marcadores genéticos, y permitieron establecer el sexo y las relaciones de parentesco.
Abstract Introduction: DNA extracted from ancient human bones allows to analyze the genetic makeup of preColumbian populations and to determine the dynamics that gave rise to the diversity of contemporary populations. Objective: To determine the genetic diversity of skeletal remains associated with the Templo del Sol (Sun Temple) and their relationship with other contemporary and ancient communities of America. Materials and methods: We analyzed 13 individuals belonging to the pre-Columbian Muisca Period (IX-XVI centuries AD) from the vicinities of the Templo del Sol (Sun Temple) (Sogamoso, Boyacá) in the eastern Colombian Andes. Mitochondrial DNA was amplified and RFLPs were performed in order to type the four traditional Amerindian haplogroups (A, B, C and D). In addition, autosomal markers including amelogenin and Y-chromosome STRs were amplified. Results: Among the observed mitochondrial lineages, haplogroup A was the most frequent, followed by haplogroups B and C; no evidence of haplogroup D was found. The genetic variation analysis indicated a similar diversity of pre-Columbian Muiscas to that of contemporary populations belonging to the Chibcha linguistic family from Colombia and Central America. Molecular sexing was accomplished and it was compared to osteological data. With only one exception, anthropological and molecular data were consistent. Conclusions: Our results contribute new genetic elements supporting the hypothesis of Central American origin of the Chibcha groups of the Cundiboyacense plateau, and allowed sex typing and kinship evaluations.
Assuntos
Feminino , História Antiga , História Medieval , Humanos , Masculino , Variação Genética , DNA Mitocondrial/genética , Indígenas Sul-Americanos/genética , Filogenia , Osso e Ossos/química , Haplótipos , Polimorfismo de Fragmento de Restrição , Indígenas Sul-Americanos/história , Marcadores Genéticos , Análise de Sequência de DNA , Colômbia , Cromossomos Humanos Y/genética , Amelogenina/genéticaRESUMO
Abstract. The mechanisms involved in the development of dental fluorosis are still unknown. The development of in vivo and in vitro models using biologically relevant concentrations of fluoride for the emergence of fluorosis has allowed suggesting hypotheses that contribute to the understanding of the mechanisms that produce this defect in enamel development, with high prevalence in Colombia. This topic review presents an update on the normal mechanisms of the formation of enamel and how they are affected by exposure to high concentrations of fluoride. This is a thorough review of the deleterious effects of fluoride on the cells and the extracellular matrix, especially during the maturation stage, resulting in a delay of the removal of the protein matrix of amelogenins, as well as the appearance of mottled enamel-a characteristic of dental fluorosis. Finally, it shows the perspectives of the study of this defect in enamel development from biochemistry and cellular and molecular biology.
RESUMEN. Los mecanismos involucrados en el desarrollo de la fluorosis dental aún no se conocen a cabalidad. El desarrollo de modelos in vivo e in vitro que utilizan concentraciones de fluoruro biológicamente relevantes para la aparición de fluorosis ha permitido el planteamiento de hipótesis que aportan cada vez más al conocimiento de los mecanismos que generan este defecto del desarrollo del esmalte, de alta prevalencia en Colombia. Esta revisión presenta una actualización sobre los mecanismos normales de la formación del esmalte y cómo estos se ven afectados por la exposición a altas concentraciones de fluoruro. Se presenta una revisión en detalle de los efectos deletéreos del fluoruro sobre las células y sobre la matriz extracelular, especialmente durante la etapa de maduración, que tendrán como consecuencia el retraso de la remoción de la matriz proteica de amelogeninas y se traducirá en la apariencia de esmalte moteado, característica de la fluorosis dental. Por último, se muestran las perspectivas del estudio de este defecto del desarrollo del esmalte desde la bioquímica y la biología celular y molecular.
Assuntos
Amelogênese , Bioquímica , Esmalte Dentário , Fluorose DentáriaRESUMO
Tooth enamel is the hardest tissue in the body. The organic matrix configuration is provided by the main proteins amelogenin, ameloblastin and enamelysin (MMP20), an enzyme that helps to shape the matrix. The aim of this study was to determine by histochemistry the expression of amelogenin and enamelysin through the rough endoplasmic reticulum in the late stages of amelogenesis, and its expression in the Complexus golgiensis (Golgi complex / Golgi apparatus) in the early stages in human fetuses. In early stages a colocalization of both proteins inside the Golgi apparatus was found, being more evident the relationship between Golgi and amelogenin (99.92 %). In the late stage, a colocalization of both proteins and rugged endoplasmic reticulum was found. With enamelysin being more evident in relation with rough endoplasmic reticulum (99.95 %). Our findings demonstrated the presence of amelogenin and enamelysin in odontoblast and ameloblast. However, the presence of these two proteins in odontoblast remains unknown.
El esmalte dental es el tejido más duro del cuerpo. La configuración de la matriz orgánica es proporcionada por las proteínas principales amelogenina, ameloblastina y enamelisina (MMP20), una enzima que ayuda a dar forma a la matriz. El objetivo de este estudio fue determinar mediante histoquímica la expresión de amelogenina y enamelisina a través del retículo endoplasmático rugoso en las últimas etapas de la amelogénesis , y su expresión en el Complexo golgiensis en las primeras etapas de formación en fetos humanos. En las primeras etapas se observó colocalización de ambas proteínas en el interior del Complexo golgiensis, siendo más evidente la relación entre Golgi y amelogenina (99,92 %). En la última etapa, se identificó una colocalización de ambas proteínas y retículo endoplásmico rugoso. Resulto más evidente la enamelisina en relación con el retículo endoplasmático rugoso (99,95 %). Nuestros resultados demostraron la presencia de amelogenina y enamelisina en odontoblastos y ameloblastos, sin embargo se desconoce la presencia de estas dos proteínas en odontoblastos.
Assuntos
Humanos , Amelogenina/metabolismo , Proteínas do Esmalte Dentário , Retículo Endoplasmático Rugoso , Complexo de Golgi , Metaloproteinase 20 da Matriz/metabolismo , Amelogênese , ImunofluorescênciaRESUMO
INTRODUCTION: DNA extracted from ancient human bones allows to analyze the genetic makeup of pre-Columbian populations and to determine the dynamics that gave rise to the diversity of contemporary populations. OBJECTIVE: To determine the genetic diversity of skeletal remains associated with the Templo del Sol (Sun Temple) and their relationship with other contemporary and ancient communities of America. MATERIALS AND METHODS: We analyzed 13 individuals belonging to the pre-Columbian Muisca Period (IX-XVI centuries AD) from the vicinities of the Templo del Sol (Sun Temple) (Sogamoso, Boyacá) in the eastern Colombian Andes. Mitochondrial DNA was amplified and RFLPs were performed in order to type the four traditional Amerindian haplogroups (A, B, C and D). In addition, autosomal markers including amelogenin and Y-chromosome STRs were amplified. RESULTS: Among the observed mitochondrial lineages, haplogroup A was the most frequent, followed by haplogroups B and C; no evidence of haplogroup D was found. The genetic variation analysis indicated a similar diversity of pre-ColumbianMuiscas to that of contemporary populations belonging to the Chibcha linguistic family from Colombia and Central America. Molecular sexing was accomplished and it was compared to osteological data. With only one exception, anthropological and molecular data were consistent. CONCLUSIONS: Our results contribute new genetic elements supporting the hypothesis of Central American origin of the Chibcha groups of the Cundiboyacense plateau, and allowed sex typing and kinship evaluations.
Assuntos
DNA Mitocondrial/genética , Variação Genética , Indígenas Sul-Americanos/genética , Amelogenina/genética , Osso e Ossos/química , Cromossomos Humanos Y/genética , Colômbia , Feminino , Marcadores Genéticos , Haplótipos , História Antiga , História Medieval , Humanos , Indígenas Sul-Americanos/história , Masculino , Filogenia , Polimorfismo de Fragmento de Restrição , Análise de Sequência de DNARESUMO
Enamel defects in permanent and deciduous teeth may be oral manifestations of celiac disease. Sometimes they are the only sign that points to this underdiagnosed autoimmune pathology. However, the etiology of these specific enamel defects remains unknown. Based on previously reported cross-reactivity of antibodies to gliadin with the enamel proteins, amelogenin and ameloblastin, we analyzed (using immunohistochemistry) the ability of anti-gliadin IgG, produced during untreated disease, to recognize enamel organ structures. We used swine germ teeth as a tissue model because they are highly homologous to human teeth in terms of proteins and development biology. Strong staining of the enamel matrix and of the layer of ameloblasts was observed with serum samples from women with celiac disease; high IgG reactivity was found against both gliadin peptides and enamel matrix protein extract, but there was no IgG reactivity against tissue antigens. In line with these findings, the gamma globulin fraction from gliadin-immunized BALB/c mice showed a similar staining pattern to that of amelogenin-specific staining. These results strongly suggest a pathological role for antibodies to gliadin in enamel defect dentition for both deciduous and permanent teeth, considering that IgG can be transported through the placenta during fetal tooth development.
Assuntos
Órgão do Esmalte , Ameloblastos , Amelogenina , Animais , Doença Celíaca , Esmalte Dentário , Proteínas do Esmalte Dentário , Feminino , Humanos , Saúde Bucal , SuínosRESUMO
Proteins from the extracellular matrix of enamel are highly specific and necessary for proper enamel formation. Most proteins are removed from the matrix by enamel proteases before complete mineralization is achieved; however, some residual protein fragments persist in the mineralized matrix of erupted enamel. So far, only amelogenin peptides obtained by traditional bottom-up proteomics have been recovered and identified in human permanent erupted enamel. In this study, we hypothesize that other enamel-specific proteins are also found in human permanent enamel, by analysing human erupted third molars. Pulverized enamel was used to extract proteins, and the protein extract was subjected directly to liquid-chromatography coupled to tandem mass spectrometry (LC-MS/MS) without a previous trypsin-digestion step. Amelogenin and non-amelogenin proteins (ameloblastin and enamelin) were succesfully identified. The sequences of the naturally occurring peptides of these proteins are reported, finding in particular that most of the peptides from the amelogenin X-isoform come from the tyrosine-rich amelogenin peptide (TRAP) and that some were identified in all specimens. In conclusion, our LC-MS/MS method without trypsin digestion increased the coverage of identification of the enamel proteome from a few amelogenin peptides to a higher number of peptides from three enamel-specific proteins.
Assuntos
Esmalte Dentário , Amelogenina , Proteínas do Esmalte Dentário , Humanos , Isoformas de Proteínas , Proteoma , Espectrometria de Massas em TandemRESUMO
OBJECTIVE: Amelogenesis imperfecta (AI) is a group of clinically and genetically heterogeneous inherited conditions, causing alterations in the structure of enamel and chemical composition of enamel matrix during development. The objective of this study was to compare the clinical, radiographic, histological and immunohistochemical phenotypes of subjects affected with hypocalcified AI from three Chilean families and identify causal mutations in the FAM83H gene. DESIGN: The diagnosis was made using clinical, radiographic, histological and genealogical data from the patients, who were evaluated according to the classification criteria by Witkop. PCR and Sanger sequencing of the complete coding sequence and surrounding intron regions of the FAM83H gene were conducted. The structural study of the affected teeth was performed with light microscopy, scanning electron microscopy and immunohistochemistry. RESULTS: The probands of the three families were diagnosed with hypocalcified AI, but in only one of them the missense variant p.Gly557Cys was identified. This variant was not present in the SNP database or in 100 healthy controls and segregated with the disease in the affected family. Using light microscopy, a normal prismatic structure was observed in all three cases. However, the ultrastructure was found to be affected in two of the cases, showing persistence of organic matter including amelogenins. CONCLUSIONS: These results suggest that FAM83H missense mutation reported in one of the families analyzed in this study might cause a phenotype of hypocalcified enamel more attenuated with retention of amelogenin.
Assuntos
Amelogênese Imperfeita/genética , Amelogenina/genética , Mutação de Sentido Incorreto/genética , Proteínas/genética , Chile , Éxons , Feminino , Humanos , Imuno-Histoquímica , Masculino , Microscopia Eletrônica de Varredura , Linhagem , FenótipoRESUMO
Amelogenin is one of the enamel matrix proteins secreted by ameloblasts during enamel formation in tooth development. Recent studies showed that the amelogenin is expressed in chondrocyte. Lysosome-associated membrane proteins (LAMPs) have been identified as binding partner proteins to amelogenin and it has been suggested they act as signaling receptors of amelogenin. The purpose of this study is to clarify the localization of amelogenin and LAMPs in growth plate cartilage and cartilaginous nodules in micromass culture. Mouse knee joints including tibia growth plate at 4 weeks old and micromass cultures of limb bud mesenchymal cells after 2 weeks were fixed in paraformaldehyde, routinely processed, sections were cut and immunostained with amelogenin, collagen type II and type X, LAMP-1 and -3. The positive immunoreaction of amelogenin was observed both in proliferation and hypertrophic zone cartilage of growth plate after enzymatic pretreatment in immunostaining. Furthermore, cartilaginous nodules in micromass culture were immunopositive to amelogenin. The chondrocytes in the proliferation zone of the growth plate were immunopositive to LAMP-1 but weakly stained in the chondrocytes of hypertrophic zone. These observations indicate that amelogenin may be present in cartilage matrix produced in vivo and in vitro and amelogenin may involve cartilage formation through the LAMP-1 signaling pathway.
La amelogenina es una de las proteínas de la matriz del esmalte secretadas por ameloblastos durante la formación del esmalte en el desarrollo dentario. Estudios recientes demuestran que la amelogenina se expresa en los condrocitos. Las proteínas de membrana asociadas a lisosomas (LAMPs) se han identificado como proteínas de unión asociadas a la amelogenina; se ha sugerido que actúan como receptores de señalización de la amelogenina. El propósito de este estudio fue aclarar la localización de la amelogenina y las LAMPs en el cartílago de crecimiento y nódulos cartilaginosos en cultivos de micromasa. Articulaciones de la rodilla del ratón, que incluían la placa de crecimiento tibial de 4 semanas de edad y cultivos de micromasa de células mesenquimales del brote del miembro después de 2 semanas se fijaron en paraformaldehído y procesaron rutinariamente. Los cortes fueron sometidos a inmunotinción con amelogenina, colágeno tipo II y X, LAMP-1 y LAMP-3 . Se observó inmunorreacción positiva de amelogenina tanto en la zona proliferación e hipertrófica del cartílago de crecimiento después del pretratamiento enzimático. Además, los nódulos cartilaginosos en el cultivo de micromasa eran inmunopositivos para la amelogenina. Los condrocitos en la zona de proliferación de la placa de crecimiento fueron immunopositivos a LAMP-1, mientras que los condrocitos de la zona hipertrófica se tiñeron débilmente. Estas observaciones indican que la amelogenina puede estar presente en la matriz del cartílago producida tanto in vivo e in vitro, además la amelogenina puede estar implicada en la formación de cartílago mediante la vía de señalización de LAMP-1.
Assuntos
Animais , Camundongos , Proteínas de Membrana Lisossomal/metabolismo , Amelogenina/metabolismo , Coloração e Rotulagem , Imuno-Histoquímica , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Condrogênese , Proteínas de Membrana Lisossomal/genética , Camundongos Endogâmicos C57BLRESUMO
La amelogénesis imperfecta es una alteración del esmalte que se puede presentar tanto en dentición decidua como permanente con diversas consecuencias negativas para los pacientes. La presente revisión describe los criterios diagnósticos, clasificación, etiología, casos esporádicos en los que se ha relacionado con otras alteraciones clínicas o enfermedades sistémicas, y su tratamiento; enfatizando la etiología y clasificación de esta alteración puesto que son las áreas en las que se han realizado muchos avances en los últimos años, especialmente relacionado con los aspectos genéticos.
Amelogenesis imperfecta is an enamel alteration that occurs in both deciduous and permanent dentition with diverse negative consequences for the patients. The present review describes the diagnostic criteria, classification, etiology, sporadic cases in which it is related to other clinical alterations or systemic diseases, and its treatment; emphasizing in the etiology and classification of this alteration since they are the areas in which many advances have been performed in the last years, specially related to the genetic aspects.