Endocrine Abstracts

Promotion of brown adipose tissue (BAT) activity or browning of white adipose tissue has shown great potential as anti-obesity strategy in numerous preclinical models. The discovery of active BAT in humans and the recent advances in the understanding of human BAT biology and function have sparked this field of research. Pharmacological stimulation of energy expenditure to counteract obesity has always been an intriguing therapeutic concept; the identification of the specific molecular pathways of brown fat function is an important step towards developing novel agents that harness the termogenic potential of adipocytes. Two distinct strategies are currently being pursued; one is the activation of bone fide BAT, the other is the induction of BAT-like cells or beige adipocytes within white fat depots, a process called browning. Recent evidence suggests that both phenomena can occur in humans. Cold-induced promotion of BAT activity is strongly associated with enhanced thermogenesis and energy expenditure in humans and has positive effects on fat mass and glucose metabolism. Despite these encouraging results, a number of issues deserve additional attention including the distinct characteristics of human versus rodent BAT, the heterogeneity of human BAT depots, or the identification of the adipocyte precursors that can give rise to thermogenic cells in human adipose tissue. In addition, many exogenous and endogenous factors have been identified to regulate a browning program in human and mouse adipocytes. This talk summarizes the cellular and molecular mechanisms of adipocyte browning, its functional relevance for energy metabolism and the therapeutic potential for obesity.