Efeito da biofotomodulação na expressão de biomarcadores em células HUVEC submetidas à hipóxia experimental

Abstract

INTRODUCTION: Studies about the applicability of laser therapy are increasing be-cause their satisfactory results in clinical and experimental research. It is known that in vitro laser irradiation is capable of improving cell viability, increasing proliferation and decreasing death. However, there is no description in the literature about the use of laser in endothelial cells as a pretreatment. These cells have promising angiogenic potential for revascularization therapies in cases of atherosclerosis and ischemia. Therefore, laser is able to modulate the cellular metabolism becomes a therapeutic alternative in these cases. PURPOSE: The objective of the present study was to ana-lyze the effects of photobiomodulation on endothelial cells submitted to experimental hypoxia. MATERIALS AND METHODS: Human Umbilical Cord Endothelial Cell (HU-VEC) groups were irradiated with a 660nm wavelength laser, 10 mW, 1.5 J/cm2 DE for 6 seconds (Laser and Laser + Hypoxia groups). Subsequently, groups were submitted to hypoxia for 24h (Hypoxia and Laser + Hypoxia groups). In sequence, cell viability analyzes for apoptosis (Propidium Iodide) and necrosis (Annexin V), leukocyte adhe-sion molecule (CD11b) and reactive oxygen species (ROS) were performed by flow cytometry. Cells and supernatants were collected and processed for analysis of VEGF expression by real-time PCR and ELISA, respectively. RESULTS: Hypoxia decreased cell viability in HUVEC cells. Therefore, laser-treated group submitted to hypoxia did not show significant differences in cell viability, CD11b expression and ROS values. However, VEGF mRNA expression increased significantly after laser irradiation in cells submitted to hypoxia. Increased VEGF expression was not detected by ELISA in cul-ture medium of this group. CONCLUSION: We demonstrated that laser pretreatment was effective in increasing VEGF mRNA expression of HUVEC cells after hypoxia pro-tocol.