RESUMO
The aim of this in vitro study was to analyze the effect of photobiomodulation therapy (PBMT) on the proliferation and undifferentiating status of stem cell from human exfoliated deciduous teeth (SHEDs). PBMT was carried out with an aluminum gallium indium phosphide (InGaAlP) diode laser in contact and punctual mode (continuous wave, 660 nm, 20 mW, 0.028 cm2, and average energy densities of 1 (1 s), 3 (4 s), 5 (7 s), 10 (14 s), 15 (21 s), or 20 (28 s) J/cm2 per point). The immunoprofile of the SHEDs was analyzed using flow cytometry. Cell proliferation was assessed by the MTT reduction assay. Gene expressions of mesenchymal stem cell markers (OCT4, Nestin, CD90, and CD105) were assessed by RT-qPCR 48 h after PBMT. Data were compared by analysis of variance (ANOVA) and Tukey's test (p ≤ 0.05). Cells cultured under nutritional deficit and treated with PBMT at 5 J/cm2 presented similar cell growth than those of positive control group. Cell growth was significantly higher than those of other groups. Mesenchymal stem cell gene markers were still expressed after PBMT at 5 J/cm2. In a short-term analysis, PBMT increases the number of stem cells with no interference in the undifferentiated state of the irradiated cells, which opens wide possibilities for application in tissue regeneration.
Assuntos
Diferenciação Celular/efeitos da radiação , Polpa Dentária/citologia , Terapia com Luz de Baixa Intensidade , Células-Tronco/citologia , Células-Tronco/efeitos da radiação , Proliferação de Células/efeitos da radiação , Células Cultivadas , Regulação da Expressão Gênica/efeitos da radiação , Humanos , Lasers Semicondutores , Fatores de Tempo , Esfoliação de Dente/patologia , Dente Decíduo/citologiaRESUMO
The impact of high-refined carbohydrate (HC) diet on fat accumulation, adipokines secretion and systemic inflammation is well described. However, it remains unclear whether these processes affect bone remodeling. OBJECTIVE: To investigate the effects of HC diet in the alveolar bone and femur parameters. METHODS: BalbC mice were fed with conventional chow or HC diet for 12 weeks. After experimental time maxillae, femur, blood and white adipose tissue samples were collected. RESULTS: The animals feed with HC diet exhibited considerable increase of adiposity index and adipose tissue levels of TNF-α, IL-6, IL-10, IL-1ß, TGF-ß and leptin. Microtomography analysis of maxillary bone revealed horizontal alveolar bone loss and disruption of trabecular bone in mice feed with HC diet. These deleterious effects were correlated with a disturbance in bone cells and an augmented expression of Rankl/Opg ratio. Consistently, similar effects were observed in femurs, which also exhibited a reduction in bone maximum load and stiffness. CONCLUSION: Our data indicates that HC diet consumption disrupts bone remodeling process, favoring bone loss. Underlying mechanisms relies on fat tissue accumulation and also in systemic and local inflammation.