Efeito do laser de baixa intensidade sobre a adesão, proliferação e expressão gênica do fator de crescimento endotelial vascular (VEGF) e do receptor 2 de VEGF em células-tronco mesenquimais cultivadas em deficiência nutricional

Abstract

In recent years, mesenchymal stem cells have been largely used in tissue engineering and regenerative medicine, for example, in post-myocardial infarction. Low level lasertherapy has been shown to promote the proliferation of several cell types, including mesenchymal stem cells (MSCs) in culture. However, it appears necessary to better understanding the use of laser therapy in preconditioning of MSCs. In this study, we used MSCs extracted from human adipose tissue (hMSC) and rat (rMSC) in culture. To analyze the effect of the low level lasertherapy and nutritional deficiency on cell behavior were observed parameters such as adhesion, proliferation and gene expression of VEGF and VEGF-R2. A dose-response curve was performed with cells treated with laser Ga-Al-As (660 nm, 30 mW) at doses of 0.7J, 1.5J, 3J and 9J. Cell adhesion and proliferation were quantified after 20, 40 and 60 minutes and 24, 72 and 120 hours of culture. Also the gene expression was verified by RT-PCR after 2 hours of irradiation. Cell proliferation of human stem cells in 5% FBS was stimulated significantly in a dose of 0,7J at 24h after irradiation. The gene expression of VEGF and VEGF receptor 2 human under 5% FBS condition was higher at doses of 0.7J, 1.5J and 3J. In the default condition, only the dose of 0.7J resulted in an increase in VEGF mRNA and its receptor. In rat cells, the expression of VEGF increased with the dose of 1.5J at condition in 5% FBS, and with the dose of 3J in standard condition. Regarding to the VEGF receptor, gene expression was stimulated in a dose of 3J in both conditions. In this study proliferation of human stem cells increased in 10% condition at a dose of 0.7J and after 24h. Added to this, the expression of VEGF and its receptor increased with low level lasertherapy, especially in impaired nutritional conditions.