High-fat diet induces emergence of brown-like adipocytes in white adipose tissue of spontaneously hypertensive rats.

ABSTRACT

Obesity has a profound adverse impact on health. In this study, we present evidence for high-fat diet (HFD)-induced emergence of brown-like adipocytes in white adipose tissue (WAT) of the spontaneously hypertensive rat (SHR). We studied adult males fed a HFD or normal diet (ND) for 12 weeks. At the end of the 12-week dietary intervention, HFD compared with ND rats showed significantly higher whole-body energy expenditure. HFD vs. ND rats also showed higher expression of genes involved in fatty acid oxidation, mitochondrial biogenesis and brown fat adipogenesis, as well as augmented mitochondrial mass in WAT but not in the liver or skeletal muscle. Consistent with the molecular changes, in HFD but not in ND rats, histological and immunohistochemistry-based analyses of WAT demonstrated the presence of small multilocular cells staining positively for uncoupling protein 1, indicating the emergence of brown-like adipocytes in WAT. Our results suggest that SHR may have the capacity to increase energy expenditure in response to a chronic HFD that may be linked to the emergence of brown-like adipocytes in WAT. Thus, the SHR may be an important genetic model to uncover novel mechanisms of resistance to dietary obesity.