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J Cutan Pathol ; 35(8): 731-7, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18430044


BACKGROUND: Cadherins and integrins are important for maintenance of tissue integrity and in signal transduction during skin development. Distribution of these molecules in human skin development was investigated and associated with markers of differentiation, cytokeratins (CK) and involucrin (INV). METHODS: Using immunohistochemistry expression of E- and P-cadherins, integrins beta-1 and -4, CK10, CK14 and INV was assessed in skin fragments of 10 human fetuses (gestational weeks ranged from 4 to 24, all weighing up to 500 g). RESULTS: At initial phases of development, integrins beta-1 and -4 and E- and P-cadherins were present on epithelial cell membranes in all layers. CK14 and CK10 were expressed in all epithelial layers and INV weakly detected in the superficial layer. In more advanced stages, integrins were detected in all layers, but a marked polarized expression was seen in basal layer. E-cadherin was detected in all layers, but the cornified stratum and P-cadherin were observed in the lower layers. CK14 was expressed in basal layer, CK10 in suprabasal stratum and INV was observed in cornified layer. CONCLUSIONS: Cadherins and integrins are essential for skin development, being spatially and temporally regulated. Their expression is related with the expression of maturation markers of the epidermis.

Antígenos de Diferenciação/biossíntese , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Pele/embriologia , Caderinas/biossíntese , Epitélio/embriologia , Humanos , Integrinas/biossíntese , Queratinas/biossíntese , Precursores de Proteínas/biossíntese , Pele/citologia
Pediatr Dev Pathol ; 11(3): 206-12, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18078367


Transforming growth factor-beta (TGF-beta) is a multifunctional growth factor that has several biological effects in vivo, including control of cell growth and differentiation, cell migration, lineage determination, motility, adhesion, apoptosis, and synthesis and degradation of extracellular matrix, and TGF-beta plays an important role in regulating tissue repair and regeneration. Our study analyzed the participation of TGF-beta 1, -beta 2, and -beta 3 in the different stages of morphogenesis and differentiation of human developing dental organ using immunohistochemistry. The maxillae and mandibles of 10 human embryos ranging from 8 to 23 weeks of gestation were employed, according to the approval of the ethical committee. Our study revealed that the TGF-beta subunits-beta 1, beta 2, and beta 3-were present in the various stages of tooth development, but the expression varied according to the differentiation stage, tissue, and TGF-beta subunit. Our results indicated that TGF-beta 1 is closely related to differentiation of enamel organ and initiation of matrix secretion, TGF-beta 2 to cellular differentiation, and TGF-beta 3 to mineral maturation matrix.

Odontogênese/fisiologia , Dente/embriologia , Fator de Crescimento Transformador beta1/biossíntese , Fator de Crescimento Transformador beta2/biossíntese , Fator de Crescimento Transformador beta3/biossíntese , Embrião de Mamíferos , Humanos , Imuno-Histoquímica , Dente/metabolismo