The best-characterized function of brown and beige fat is thermogenesis through uncoupling protein 1 (UCP1). Accordingly, the prevailing dogma was that enhanced thermogenesis by UCP1 exclusively mediates all the action of brown/beige fat, through which we observe metabolic improvements in the form of anti-obesity and anti-diabetic effects.
However, emerging evidence suggests that the anti-obesity and anti-diabetic actions of beige fat are UCP1-independent. Mechanistically, we identified UCP1-independent mechanisms that involve Ca2+ cycling thermogenesis, repression of adipose tissue inflammation and fibrosis, secretion of a batokine, and enhanced clearance of branched-chain amino acids. I'll discuss our new studies pertinent to UCP1-independent pathways that control energy homeostasis.