Browning plasticity of white adipose tissue in tree shrew during cold acclimation and rewarming

Abstract

This study investigated the browning plasticity of white adipose tissue (WAT) in Tupaia belangeri during cold acclimation and rewarming in order to demonstrate the adaptation mechanism of tree shrews to environmental change. The experimental group was transferred to a cold temperature, 5 ± 1 °C, acclimated for 28 d, and then returned to 25 ± 1 °C for 28 d, while the control group was maintained at the acclimation temperature, 25 ± 1 °C, for 56 d. Body mass, food intake, resting metabolic rate (RMR), WAT mass, morphology and related gene expression in male T. belangeri were measured. The results showed that body mass, food intake and RMR increased significantly under cold acclimation. There was also a significant increase in WAT mass and expression of peroxisome proliferation receptor α (PPARα), peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), cyclooxygenaseII (COXII), bone morphogenetic protein 7 (BMP7) and the PR domain containing 16 (PRDM16), all of which decreased to control levels after rewarming. Further, WAT cells showed more multilocule adipocytes during cold acclimation, which returned to control levels after rewarming. These results suggest that browning may appear in the WAT of T. belangeri during cold acclimation. The return to control levels of WAT cell characteristics and expression of the genes involved in WAT browning after rewarming demonstrates strong browning plasticity.