AT1 receptor antagonist induces thermogenic beige adipocytes in the inguinal white adipose tissue of obese mice

To evaluate whether losartan is able to induce beige adipocytes formation, focusing on the thermogenic gene expression and adipocyte remodeling in the subcutaneous white adipose tissue of diet-induced obese mice. Male C57BL/6 mice received a control diet (10% energy as lipids) or a high-fat diet (50% energy as lipids) for 10 weeks, followed by a 5-week treatment with losartan: control group, control-losartan group (10 mg/Kg/day), high-fat group and high-fat-losartan group (10 mg/Kg/day). Biochemical, morphometrical, stereological and molecular approaches were used to evaluate the outcomes. The high-fat diet elicited overweight, insulin resistance and adipocyte hypertrophy in the high-fat group, all of which losartan rescued in the high-fat-losartan group. These effects comply with the induction of beige adipocytes within the inguinal fat pads in high-fat-losartan group as they exhibited the greatest energy expenditure among the groups along with the presence uncoupling protein 1 positive multilocular adipocytes with enhanced peroxisome proliferator-activated receptor gamma coactivator 1-alpha and PR domain containing 16 mRNA levels, indicating a significant potential for mitochondrial biogenesis and adaptive thermogenesis. Our results show compelling evidence that losartan countered diet-induced obesity in mice by enhancing energy expenditure through beige adipocytes induction. Reduced body mass, increased insulin sensitivity, decreased adipocyte size and marked expression of uncoupling protein 1 by ectopic multilocular adipocytes support these findings. The use of losartan as a coadjutant medicine to tackle obesity and its related disorders merits further investigation.