Photobiomodulation activates glucose uptake in brown adipose tissue of obese mice

Abstract

Mammal fat consists ofwhite and brown adipose tissues (WATand BAT). Although most fat is energy-storing WAT, brown adipocytes dissipate energy as heat. Obese subjects exhibit BAT hyporesponsiveness to classical stimuli as cold, hence increasing BAT thermogenic capacity could be an i n t er e s t i n g t a rget f o r t r eating obesity. Photobiomodulation (PBM) seems to be a feasible alternative to activate BAT, although it has not been applied for this purpose until now. In this study, adult C57Bl/6 mice were fed with a hyperlipidic diet (HF) during 15 weeks to induce obesity. Then, they were divided into two groups: HF and HF660. The interscapular BAT of HF660 mice was exposed to a single irradiation using a 662 ± 20 nm LED (5.7 Jcm-2 at 19 mWcm-2, delivered during 300 s). The HF group was sham-irradiated. Eutrophic animals were also used. Animals received 200 mCi of 18F-FDG and were exposed to cold for basal register of PET-CT images. After PBM or sh am treat ment, mice were once again exposed to cold before PET-CT image acquisition. Our results showed that PBM was able to activate BAT in obese mice through higher glucose uptake. In contrast, PBM and shamirradiated normal fed mice presented similar levels of glucose uptake. Taking together, our findings suggest that PBM applied to the BAT is able to promote glucose uptake by obese mice and could be an interesting approach to manage obesity and its correlated morbidities.