Combined α- and β-adrenergic receptor activation triggers thermogenesis by the futile creatine cycle.

Noradrenaline regulates cold-stimulated adipocyte thermogenesis. Aside from cAMP signaling downstream of β-adrenergic receptor (βAR) activation, how noradrenaline promotes thermogenic output is still not fully understood. Here, we show that coordinated α1-adrenergic receptor (α1AR) and β3AR signaling induces the expression of thermogenic genes of the futile creatine cycle, and that EBFs, ERRs, and PGC1α are required for this response in vivo. Noradrenaline triggers physical and functional coupling between the α1AR subtype (ADRA1A) to Gαq to promote adipocyte thermogenesis in a manner that is dependent on the effector proteins of the futile creatine cycle, creatine kinase b (CKB) and tissue-nonspecific alkaline phosphatase (TNAP). Combined Gαq and Gαs signaling selectively in adipocytes promotes a continual rise in whole-body energy expenditure, and CKB is required for this effect. Thus, the ADRA1A-Gαq-futile creatine cycle axis is a key regulator of facultative and adaptive thermogenesis. Comparative gene expression profiling analysis of RNA-seq data for brown adipose tissue (either 30°C or 6°C) with saline solution or PBZ injections.