New Advances in Adaptive Thermogenesis: UCP1 and Beyond.

Brown and beige adipocytes can catabolize stored energy to generate heat, and this distinct capacity for thermogenesis could be leveraged as a therapy for metabolic diseases like obesity and type 2 diabetes. Thermogenic adipocytes drive heat production through close coordination of substrate supply with the mitochondrial oxidative machinery and effectors that control the rate of substrate oxidation. Together, this apparatus affords these adipocytes with tremendous capacity to drive thermogenesis. The best characterized thermogenic effector is uncoupling protein 1 (UCP1). Importantly, additional mechanisms for activating thermogenesis beyond UCP1 have been identified and characterized to varying extents. Acute regulation of these thermogenic pathways has been an active area of study, and numerous regulatory factors have been uncovered in recent years. Here we will review the evidence for regulators of heat production in thermogenic adipocytes in the context of the thermodynamic and kinetic principles that govern their therapeutic utility.