Brown adipose tissue (BAT), characterized by the presence of uncoupling protein 1 (UCP1), has been described as metabolically active in humans. Lou/C rats, originating from the Wistar strain, are resistant to obesity. We previously demonstrated that Lou/C animals express UCP1 in beige adipocytes in inguinal white adipose tissue (iWAT), suggesting a role of this protein in processes such as the ...

In vitro experiments suggest that stimulation of lipolysis by catecholamines in adipocytes depends on the energy status of these cells. We tested whether mitochondrial uncoupling proteins (UCPs) that control the efficiency of ATP production could affect lipolysis and noradrenaline signalling in white fat in vivo. The lipolytic effect of noradrenaline was lowered by ectopic UCP1 in white adipocy...

Beta3-adrenergic receptors (AR) are nearly exclusively expressed in brown and white adipose tissues, and chronic activation of these receptors by selective agonists has profound anti-diabetes and anti-obesity effects. This study examined metabolic responses to acute and chronic beta3-AR activation in wild-type C57Bl/6 mice and congenic mice lacking functional uncoupling protein (UCP)1, the mole...

Most physiologically induced examples of recruitment of brown adipose tissue (BAT) occur as a consequence of chronic sympathetic stimulation (norepinephrine release within the tissue). However, in some physiological contexts (e.g., prenatal and prehibernation recruitment), this pathway is functionally contraindicated. Thus a nonsympathetically mediated mechanism of BAT recruitment must exist. H...

Brown adipose tissue expressing uncoupling protein 1 (UCP1) is responsible for adaptive nonshivering thermogenesis giving eutherian mammals crucial advantage to survive the cold. The emergence of this thermogenic organ during mammalian evolution remained unknown as the identification of UCP1 in marsupials failed so far. Here, we unequivocally identify the marsupial UCP1 ortholog in a genomic li...

Adaptive thermogenesis allows mammals to resist to cold. For instance, in brown adipose tissue (BAT) the facultative uncoupling of the proton gradient from ATP synthesis in mitochondria is used to generate systemic heat. However, this system necessitates an increase of the Uncoupling protein 1 (Ucp1) and its activation by free fatty acids. Here we show that mice without functional Period2 (Per2...

Brown fat generates heat via the mitochondrial uncoupling protein UCP1, defending against hypothermia and obesity. Recent data suggest that there are two distinct types of brown fat: classical brown fat derived from a myf-5 cellular lineage and UCP1-positive cells that emerge in white fat from a non-myf-5 lineage. Here, we report the isolation of "beige" cells from murine white fat depots. Beig...

Brown adipose tissue (BAT) thermogenesis is inhibited during late-pregnancy and lactation in the rat. However, scarce information concerning BAT functionality during mid-pregnancy is available. The aim of this work was to investigate uncoupling proteins and leptin expression during placentation in rat BAT as well as other key parameters in the thermogenic function of the tissue. BAT mitochondri...

Igniting thermogenesis within white adipose tissue (i.e., promoting expression and activity of the uncoupling protein UCP1) has attracted much interest. Numerous "browning agents" have now been described (gene ablations, transgenes, food components, drugs, environments, etc.). The implied action of browning agents is that they increase UCP1 through this heat production, leading to slimming. Her...

Adaptive adrenergic thermogenesis – both the form that develops subsequent to cold acclimation and the form that develops subsequent to a palatable diet challenge – is entirely dependent on the presence and activity of the brown fat uncoupling protein, UCP1. In a cold environment, the absence of UCP1 can be compensated by alternative means, such as shivering or exercise. Upon a challenge with a...