Gene expression analysis of environmental temperature and high-fat diet-induced changes in mouse supraclavicular brown adipose tissue

Authors: SHI, YUFENG - Children'S Nutrition Research Center (CNRC); ZHAI, HONGLEI - Children'S Nutrition Research Center (CNRC); SHARON, JOHN - Children'S Nutrition Research Center (CNRC); SHEN, YI-TING - Children'S Nutrition Research Center (CNRC); RAN, YALI - Children'S Nutrition Research Center (CNRC); HOANG, GIANG - Children'S Nutrition Research Center (CNRC); CHEN, MIAO-HSUEH - Children'S Nutrition Research Center (CNRC)

Submitted to: Cells
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/29/2021
Publication Date: 6/2/2021
Citation: Shi, Y., Zhai, H., Sharon, J., Shen, Y., Ran, Y., Hoang, G., Chen, M. 2021. Gene expression analysis of environmental temperature and high-fat diet-induced changes in mouse supraclavicular brown adipose tissue. Cells. 10(6):1370. https://doi.org/10.3390/cells10061370.
DOI: https://doi.org/10.3390/cells10061370

Interpretive Summary: Brown fat burns fat and sugar to generate heat that can be useful for maintaining body temperature in cold weather and preventing obesity. Previously, we identified a novel brown fat tissue in the mouse neck that is similar to the neck brown fat in humans. In this paper, we determined how environmental temperatures and high-fat diet affect the function of mouse neck brown fat. Like in human neck brown fat, cold temperatures stimulated mouse neck brown fat to burn fat and sugar to maintain body temperature, while high-fat diet altered the appearance of and reduced the function of the neck brown fat. Together, these studies showed that mouse neck brown fat is a suitable animal model for studying the function of human brown fat.

Technical Abstract: Obesity, a dysregulation of adipose tissue, is a major health risk factor associated with many diseases. Brown adipose tissue (BAT)-mediated thermogenesis can potentially regulate energy expenditure, making it an attractive therapeutic target to combat obesity. Here, we characterize the effects of cold exposure, thermoneutrality, and high-fat diet (HFD) feeding on mouse supraclavicular BAT (scBAT) morphology and BAT-associated gene expression compared to other adipose depots, including the interscapular BAT (iBAT). scBAT was as sensitive to cold induced thermogenesis as iBAT and showed reduced thermogenic effect under thermoneutrality. While both scBAT and iBAT are sensitive to cold, the expression of genes involved in nutrient processing is different. The scBAT also showed less depot weight gain and more single-lipid adipocytes, while the expression of BAT thermogenic genes, such as Ucp1, remained similar or increased more under our HFD feeding regime at ambient and thermoneutral temperatures than iBAT. Together, these findings show that, in addition to its anatomical resemblance to human scBAT, mouse scBAT possesses thermogenic features distinct from those of other adipose depots. Lastly, this study also characterizes a previously unknown mouse deep neck BAT (dnBAT) depot that exhibits similar thermogenic characteristics as scBAT under cold exposure and thermoneutrality.