RESUMO
We examined alveolar bone samples in the area of on-bone fixation of a free gingival graft performed during surgery in patients aged 37-55 years with a diagnosis of secondary partial adentia of the upper and lower jaws. Six months after fixation of the graft in the alveolar bone, foci of neoosteogenesis were found in the contact zone. They were characterized by the appearance of appositional lines, cords of basophilic osteoblasts, and growing osteons. An immunohistochemical study revealed an increase in the number of CD44+, CD29+, and osteocalcin+ cells in the layer of the outer circumferential lamellae, primary osteons, and the lining of the Haversian canals. TGF-ß1+ cells were located in the intertrabecular reticular tissue and wall of microvessels. The results indicate activation of mesenchymal stem cells in the area of localization of the graft and differentiating osteoblasts. The observed osteoinductive effect of free gingival graft is associated with its participation in reorganization in MSC and induction of morphogenetic molecules.
Assuntos
Processo Alveolar/fisiologia , Implantação Dentária/métodos , Gengiva/transplante , Arcada Parcialmente Edêntula/terapia , Osseointegração/fisiologia , Adulto , Enxerto de Osso Alveolar/métodos , Processo Alveolar/citologia , Aumento do Rebordo Alveolar/métodos , Remodelação Óssea/genética , Diferenciação Celular/genética , Feminino , Retalhos de Tecido Biológico/fisiologia , Gengiva/metabolismo , Gengiva/patologia , Humanos , Receptores de Hialuronatos/genética , Receptores de Hialuronatos/metabolismo , Integrina beta1/genética , Integrina beta1/metabolismo , Arcada Parcialmente Edêntula/genética , Arcada Parcialmente Edêntula/patologia , Arcada Parcialmente Edêntula/fisiopatologia , Masculino , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/fisiologia , Pessoa de Meia-Idade , Osseointegração/genética , Osteocalcina/genética , Osteocalcina/metabolismo , Osteogênese/genética , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/metabolismoRESUMO
INTRODUCTION: Hypodontia, agenesis of one or of more teeth, is a common developmental dental anomaly. To date, over 200 candidate genes have been demonstrated to be active in tooth development. The genes Pax9 plays an important role in the initial stage of odontogenesis. Mutations of Pax9 are associated with autosomal dominant forms of oligodontia, the agenesis of more than six teeth and occasionally of premolars (MIM 604625) in humans. The aim of the present study was to screen the candidate gene causing the non syndromic hypodontia, with agenesis of upper third molars and upper lateral incisors, in three couples of twins. MATERIALS AND METHODS: Peripheral blood samples taken for routine laboratory investigations were used for genotyping. Total genomic DNA was extracted from the buffy coat of 1 ml of EDTA blood samples using phenol-chloroform and the salting out procedure. RESULTS: The insC mutation (nt793, exon4) was observed in the sequencing results by the use of the primers hPAX9ex4F and hPAX9ex4R. InsC raises a frameshift mutation that introduces a nonsense codon so the mRNA activity results impaired. CONCLUSION: In this work, it is described how the same mutation is responsible for a form of dental agenesis--less severe in the number of missing teeth--leading to hypodontia instead of oligodontia. Therefore, it is possible that mutations of the same gene cause different phenotypes; so we can presume that some modifier genes moderate the effect of the first mutation.
Assuntos
Anodontia/genética , Doenças em Gêmeos/genética , Arcada Parcialmente Edêntula/genética , Fator de Transcrição PAX9/genética , Feminino , Humanos , Incisivo/anormalidades , Mandíbula , Maxila , Dente Serotino/anormalidades , Gêmeos MonozigóticosRESUMO
BACKGROUND AND OBJECTIVE: Expression of p21 and p53 were examined, at gene and protein levels, in edentulous gingival epithelial cells from rats and from a human oral epidermoid carcinoma cell line, OECM1, after cyclosporine A therapy. MATERIAL AND METHODS: In vivo: 20 partially edentulous SD rats were assigned into cyclosporine A feeding and control groups. After the rats were killed, p21 and p53 in gingiva were evaluated by reverse transcription-polymerase chain reaction and immunohistochemistry. In vitro: after cyclosporine A treatment, p21 and p53 of OECM1 cells were evaluated by western blot and the luciferase assay. The distribution of OECM1 cells in each phase of the cell cycle was evaluated by flow cytometry. RESULTS: The mRNA expression of p21 was significantly higher in the cyclosporine A group than in the control group. A greater number of positive anti-p21-stained cells were observed in the gingival epithelium of the cyclosporine A group than in the control group. Significantly higher levels of p21 protein and activity were observed in OECM1 cells after cyclosporine A treatment than in cells without treatment. A relative increase of cells in G0/G1 phases, and a decrease of cells in G2/M phases, were observed in OECM1 cells after cyclosporine A treatment. CONCLUSION: In the present study, higher p21 mRNA and protein expressions were observed after cyclosporine A treatment. Thus, an up-regulation of p21 expression, via a p53-independent pathway, by cyclosporine A in gingival and oral epithelial cells was suggested.
Assuntos
Inibidor de Quinase Dependente de Ciclina p21/análise , Ciclosporina/uso terapêutico , Genes p53/efeitos dos fármacos , Imunossupressores/uso terapêutico , Proteína Supressora de Tumor p53/análise , Animais , Carcinoma de Células Escamosas , Linhagem Celular Tumoral , Células Epiteliais/efeitos dos fármacos , Gengiva/química , Gengiva/citologia , Gengiva/efeitos dos fármacos , Humanos , Arcada Parcialmente Edêntula/enzimologia , Arcada Parcialmente Edêntula/genética , RNA Mensageiro/análise , RatosRESUMO
Ectodermal dysplasia with arthrogryposis is an uncommon condition. We describe two daughters of a distant consanguineous couple with oligodentia, enamel abnormalities, camptodactyly, longitudinally broken nails, growth retardation, joint contractures with amyotrophy, hypohidrotic skin with tendency to excessive bruising and scarring after injuries and scratching, kypho-scoliosis, mild facial dysmorphia and microcephaly. The condition is probably due to an autosomal recessive gene, the parents being gypsies of the same ancestral origin.
