The beneficial effects of brown adipose tissue transplantation.

Obesity is a disease that results from an imbalance between energy intake and energy expenditure. Brown adipose tissue (BAT) is a potential therapeutic target to improve the comorbidities associated with obesity due to its inherent thermogenic capacity and its ability to improve glucose metabolism. Multiple studies have shown that activation of BAT using either pharmacological treatments or cold exposure had an acute effect to increase metabolic function and reduce adiposity. Recent preclinical investigations have explored whether increasing BAT mass or activation through transplantation models could improve glucose metabolism and metabolic health. Successful BAT transplantation models have shown improvements in glucose metabolism and insulin sensitivity, as well as reductions in body mass and decreased adiposity in recipients. BAT transplantation may confer its beneficial effects through several different mechanisms, including endocrine effects via the release of 'batokines'. More recent studies have demonstrated that beige and brown adipocytes isolated from human progenitor cells and transplanted into mouse models result in metabolic improvements similar to transplantation of whole BAT; this could represent a clinically translatable model. In this review we will discuss the impetus for both early and recent investigations utilizing BAT transplantation models, the outcomes of these studies, and review the mechanisms associated with the beneficial effects of BAT transplant to confer improvements in metabolic health.