Activation of b-adrenergic receptor signaling prevents glucocorticoid-induced obesity and adipose tissue dysfunction in male mice

Elevated serum concentrations of glucocorticoids (GCs) result in excessive lipid accumulation in white adipose tissue (WAT) as well as dysfunction of thermogenic brown adipose tissue (BAT), ultimately leading to the development of obesity and metabolic disease. Here, we hypothesized that activation of the sympathetic nervous system either via cold exposure or the use of a selec-tive I33-adrenergic receptor (I33-AR) agonist alleviates the adverse metabolic effects of chronic GC exposure in rodents. To this end, male 10-wk-old C57BL/6NRj mice were treated with corticosterone via drinking water or placebo for 4 wk while being main-tained at 29 degrees C (thermoneutrality), 22 degrees C (room temperature), or 13 degrees C (cold temperature); in a follow-up study mice received a selective I33-AR agonist or placebo with and without corticosterone while being maintained at room temperature. Body weight and food intake were monitored throughout the study. Histological and molecular analyses were performed on white and brown adipose depots. Cold exposure not only preserved the thermogenic function of brown adipose tissue but also reversed GC -induced lipid accumulation in white adipose tissue and corrected GC-driven obesity, hyperinsulinemia, and hyperglycemia. The metabolic benefits of cold exposure were associated with enhanced sympathetic activity in adipose tissue, thus potentially link-ing an increase in sympathetic signaling to the observed metabolic benefits. In line with this concept, chronic administration of a selective I33-AR agonist reproduced the beneficial metabolic effects of cold adaption during exposure to exogenous GCs. This preclinical study demonstrates the potential of I33-AR as a therapeutic target in the management and prevention of GC-induced metabolic disease. NEW & NOTEWORTHY This preclinical study in mice shows that the I33-adrenergic receptor can be a potential therapeutic approach to counteracting glucocorticoid (GC)-induced obesity and metabolic dysfunction. Both cold acclimation and I33-adrener-gic receptor stimulation in a mouse model of excess glucocorticoids were adequate in not only preventing obesity, adiposity, and adipose tissue dysfunction but also correcting hyperinsulinemia, hyperleptinemia, and dyslipidemia.