RESUMEN
BACKGROUND AND OBJECTIVE: Ciclosporin A (CsA)-induced gingival overgrowth is attributed to an exaggerated accumulation of extracellular matrix, which is mainly due to an increased expression of transforming growth factor-ß1 (TGF-ß1). Herein, the in vitro investigation of effects of overexpression of Smad7, a TGF-ß1 signaling inhibitor, in the events associated with CsA-induced extracellular matrix accumulation was performed. MATERIAL AND METHODS: The effects of Smad7 were assessed by stable overexpression of Smad7 in fibroblasts from normal gingiva. Smad7-overexpressing cells and control cells were incubated with CsA, and synthesis of type I collagen, production and activity of MMP-2 and cellular proliferation were evaluated by ELISA, zymography, growth curve, bromodeoxyuridine incorporation assay and cell cycle analysis. The effects of CsA on cell viability and apoptosis of fibroblasts from normal gingiva were also evaluated. Western blot and immunofluorescence for phospho-Smad2 were performed to measure the activation of TGF-ß1 signaling. RESULTS: Although the treatment with CsA stimulated TGF-ß1 production in both control and Smad7-overexpressing fibroblasts, its signaling was markedly inhibited in Smad7-overexpressing cells, as revealed by low levels of phospho-Smad2. In Smad7-overexpressing cells, the effects of CsA on proliferation, synthesis of type I collagen and the production and activity of MMP-2 were significantly blocked. Smad7 overexpression blocked CsA-induced fibroblast proliferation via p27 regulation. Neither CsA nor Smad7 overexpression induced cell death. CONCLUSION: The data presented here confirm that TGF-ß1 expression is related to the molecular events associated with CsA-induced gingival overgrowth and suggest that Smad7 overexpression is effective in blocking these events, including proliferation, type I collagen synthesis and MMP-2 activity.
Asunto(s)
Ciclosporina/efectos adversos , Fibroblastos/efectos de los fármacos , Encía/efectos de los fármacos , Sobrecrecimiento Gingival/inducido químicamente , Proteína smad7/farmacología , Antimetabolitos , Apoptosis/efectos de los fármacos , Bromodesoxiuridina , Técnicas de Cultivo de Célula , Ciclo Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Colágeno Tipo I/efectos de los fármacos , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/metabolismo , Ciclosporina/antagonistas & inhibidores , Matriz Extracelular/efectos de los fármacos , Matriz Extracelular/metabolismo , Fibroblastos/metabolismo , Regulación de la Expresión Génica/genética , Encía/citología , Encía/metabolismo , Humanos , Masculino , Metaloproteinasa 2 de la Matriz/efectos de los fármacos , Fosforilación , Inhibidores de Proteínas Quinasas/metabolismo , Transducción de Señal/efectos de los fármacos , Proteína Smad2/efectos de los fármacos , Proteína smad7/genética , Transfección , Factor de Crecimiento Transformador beta1/antagonistas & inhibidores , Adulto JovenRESUMEN
The purpose of this study was to examine the effect of two between set rest intervals (RI) on isokinetic knee extension peak torque (PT) produced by sedentary women and men. Seventeen young women (27.18 ± 4.05 yrs) and 16 young men (26.75 ± 4.73 yrs) performed 3 sets of 10 unilateral isokinetic knee extension at 60° and 180°/s. The RI between sets was 60 and 120 s, counterbalanced across 2 testing days. Statistical evaluation of the data was performed using a 3-way mixed factor ANOVA (gender x rest interval x sets). Males and females exhibited decreases (p<0.05) in PT with 120 s RI at 60°/s. There was no significant decline in PT in the female group during both RI at 180°/s. Men showed a significant decrease in PT only with 60 s RI. Young women and men require more than 120 s of RI to recover full PT at 60°/s. However, full quadriceps's muscle strength recovery can be attained with a 60 and 120 s at 180°/s in women, but in men only with a 120 s at the same velocity.
