RESUMO
The effect of low-level laser therapy (LLLT) on the healing of skin lesions has been evaluated in many studies; however, the molecular mechanisms involved in the biostimulatory effects resulting from this treatment need to be better understood. The paper aims to analyze the effects of LLLT (660 nm) at doses of 1 and 5 J/cm2 on cell viability and expression of vascular endothelial growth factor (VEGF) and interleukin (IL6) genes in L929 fibroblast cells. The dose-response curve was performed with the GaInAlAs (660 nm) laser-treated cells at energy rates of 1 and 5 J/cm2. Cell viability was quantified at 24, 48, and 72 h after irradiation and the effects of TLBP on the cytoskeleton and endoplasmic reticulum were evaluated by fluorescence microscopy and the RT-qPCR method was used for the analysis of gene expression. It was observed that the 72 h group had a statistically significant increase in cell viability compared to the 48 h group (p < 0.01) and when compared to the 72 h control (p = 0.03). In 72 h, a greater distribution of the cytoskeleton filaments and the more evident endoplasmatic reticulum was verified, indicating an increase in the protein synthesis when compared with the control group. In the expression of the VEGF gene, a significant increase of 1.98 times (p < 0.05) in the number of transcripts was observed; whereas for the IL6 gene, a decrease of the transcripts was 4.05 times (p < 0.05), both occurring within 72 h after irradiation at 5 J/cm2. The LLLT (660 nm) at the dose of 5 J/cm2 should modulate cellular viability, upregulated VEGF, and downregulated IL6 expression of messenger RNA in culture of L929 fibroblast cells.
Assuntos
Regulação da Expressão Gênica/efeitos da radiação , Terapia com Luz de Baixa Intensidade , Cicatrização/genética , Cicatrização/efeitos da radiação , Animais , Proliferação de Células/genética , Proliferação de Células/efeitos da radiação , Sobrevivência Celular/efeitos da radiação , Regulação para Baixo/efeitos da radiação , Fibroblastos/metabolismo , Fibroblastos/efeitos da radiação , Interleucina-6/genética , Interleucina-6/metabolismo , Camundongos , Microscopia de Fluorescência , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fatores de Tempo , Regulação para Cima/efeitos da radiação , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
OBJECTIVE: The purpose of the present study was to evaluate the effect of biomodulation on osteoblastic cells using a gallium-aluminium-arsenide diode laser. BACKGROUND DATA: Low-level laser therapy (LLLT) is a non-pharmacological therapeutic resource to which biological tissues respond well, producing such effects as the acceleration of bone formation and bone repair. MATERIALS AND METHODS: Osteoblastic cell cultures (OFCOL II) were irradiated with a gallium-aluminium-arsenide diode laser (GaAlAs lambda = 830 nm; 50 mW; 3 J/cm(2); 600-microm-diameter optical fiber) and divided into two groups: group 1--irradiated cells, and group 2--non-irradiated cells. Irradiation occurred at 24-h intervals for a total of 3 d. After each interval, the cells were marked with Mito Tracker Orange dye to assess the biostimulatory effect on mitochondrial activity and cell proliferation using an MTT assay. RESULTS: Intense grouping of mitochondria in the perinuclear region was observed at 24 h and 48 h following irradiation. Changes from a filamentous to a granular appearance in mitochondrial morphology and mitochondria distributed throughout the cytoplasm were observed 72 h following proliferation. Such changes led to an in vitro proliferation process, as confirmed by the MTT assay. CONCLUSION: LLLT has shown itself capable of altering mitochondrial activity and the population of OFCOL II cells.