RESUMO
[ ABSTRACT] AIM:To study the relationship between transcriptional factor c-Jun and Mepe gene expression, and to identify the specific binding site of c-Jun on the promoter of Mepe.METHODS:The expression of c-Jun and Mepe in mouse bone tissue was detected by immunolocalization assay.The mRNA expression of Mepe was determined by real-time PCR when the expression of c-Jun was changed.The techniques of dual luciferase analysis and site-specific mutagenesis were used to measure the effects of c-Jun on the transcriptional activity of Mepe.RESULTS:c-Jun was detected in the nu-cleus of osteocytes, while Mepe was observed in osteocyte cytoplasm.The results of real-time PCR showed that overexpres-sion of c-Jun directly resulted in significantly higher up-regulation of Mepe mRNA.Compared with control group, the tran-scriptional activity of Mepe promoter was increased in osteoblasts which was transfected with pCMV-3Tag-1-c-Jun.Mutation of c-Jun potential binding sites decreased the transcriptional activity of Mepe promoter.CONCLUSION:Mepe gene tran-scription can be up-regulated by c-Jun which binds to the specific sites of Mepe promoter in osteoblasts.
RESUMO
The extracellular matrix (ECM) plays an important role in the regulation of biological events such as the development of cell migration, proliferation and differentiation. Chronic sun exposure causes changes present in the ECM of actinic cheilitis (AC), a premalignant lesion of the lower lip which helps to understand the carcinogenesis of the lip. This study aimed to investigate elastin, the main component of solar elastosis alternating current in an attempt to establish the relationship between this protein and ECM in epithelial dysplasia. Paraffin embedded tissue sections of the lesions of 35 cases of AC were analyzed by immunohistochemistry for elastin, and became the association with the degree of epithelial dysplasia and age. Highest scores of elastin (+3) was predominant in 45.7 percent of cases of AC, especially in cases of severe dysplasia (n = 3). When comparing the scores of elastin between the different grades of epithelial dysplasia showed no significant difference (P> 0.05, Kruskal-Wallis). This study was not able to demonstrate the influence of elastin on the severity of epithelial dysplasia in AC. Additional studies on other ECM proteins must be conducted in an attempt to better understand the mechanism of malignant progression of the AC.
La matriz extracelular (MEC) juega un papel importante en la regulación de los eventos biológicos, tales como, el desarrollo de la migración celular, proliferación y diferenciación. La exposición solar crónica provoca cambios presentes en la MRC de la queilitis actínica (QA), una lesión premaligna del labio inferior que contribuye a entender la carcinogénesis del labio. Este estudio tuvo como objetivo investigar la elastina, el componente principal de la elastosis solar en corriente alterna en un intento de establecer la relación entre esta proteína y la MEC en displasia epitelial. Se incluyeron en parafina cortes de tejido de las lesiones de 35 casos de QC fueron analizadas mediante técnicas de inmunohistoquímica para elastina, y se hizo la asociación con los grados de displasia epitelial y la edad. La más alta puntuación de la elastina (+3) fue predominante en el 45,7 por ciento de los casos de QA, especialmente en los casos de displasia severa (n = 3). Al comparar las puntuaciones de elastina entre los diferentes grados de displasia epitelial, no mostró diferencia significativa (P> 0,05, Kruskall-Wallis). Este estudio no fue capaz de demostrar la influencia de la elastina sobre gravedad de la displasia epitelial en QA. Estudios adicionales sobre otras proteínas de la MEC deben llevarse a cabo en un intento por comprender mejor el mecanismo de progresión maligna de la QC.