B. Cariou, E. Bouchaert, M. Abdelkarim, J. Dumont, S. Caron et al.
Institut Pasteur de Lille, Département d’Athérosclérose, Lille F-59019, France
The role of the nuclear receptor FXR in adaptive thermogenesis was investigated using FXR-deficient mice. Despite elevated serum bile acid concentrations and increased mRNA expression profiles of thermogenic genes in brown adipose tissue, FXR-deficiency did not alter energy expenditure under basal conditions. However, FXR-deficiency accelerated the fasting-induced entry into torpor in a leptin-dependent manner. FXR-deficient mice were also extremely cold-intolerant. These altered responses may be linked to a more rapid decrease in plasma concentrations of metabolic fuels (glucose, triglycerides) thus impairing uncoupling protein 1-driven thermogenesis. These results identify FXR as a modulator of energy homeostasis.
BIOSEB Instruments Used:
OXYLET, Indirect Calorimeter (OXYLET)