Constitutive and recruitable brown adipose tissue (cBAT and rBAT, the latter also called beige or brite adipose tissue) co-regulate thermogenesis and energy homeostasis in mice, shows a new study.

“To specifically target one of the two populations of brown adipocytes would help determine whether the recruitable beige/brite adipocytes within white adipose tissue (WAT) have similar thermogenic capacity to the constitutive brown adipocytes present in interscapular locations,” explains study researcher Tim Schulz.

Schulz et al. generated a mouse model lacking expression of BMP type 1A receptor in cells of the myogenic lineage, which severely reduced the mass of cBAT but not that of rBAT. Interestingly, the formation of rBAT was stimulated in cBAT-poor animals, via increased sympathetic signalling to WAT. As a result of this compensatory 'browning' of adipose tissue, adult mutant mice displayed normal thermogenic capacity and were resistant to diet-induced obesity.

“One could design drugs that mimic BMP's 'browning' effect for the treatment and/or prevention of metabolic diseases,” says Yu-Hua Tseng, senior investigator of the study. Targeting the crosstalk mechanisms involving different BAT depots and the sympathetic nervous system to treat obesity “may have to take into account that compensatory mechanisms are in place that could counter the beneficial effects of such strategies to increase the antiobesogenic effects of BAT,” notes Schulz.