Abstract
Brownadipose tissue (BAT)is specialized in energy expenditure,making it a potential target for anti-obesity therapies1-5. Following exposure to cold,BATis activated by the sympathetic nervous systemwith concomitant release of catecholamines and activation of β-adrenergic receptors1-5.BecauseBATtherapiesbasedoncold exposureor β-adrenergic agonists are clinically not feasible, alternative strategies must be explored. Purinergic co-transmissionmight be involved in sympathetic control of BAT and previous studies reported inhibitory effects of the purinergic transmitter adenosine inBATfromhamster or rat6-8. However, the role of adenosine in human BATis unknown. Here we show that adenosine activates human and murine brown adipocytes at low nanomolar concentrations.Adenosine is releasedinBATduring stimulation of sympathetic nerves as well as frombrown adipocytes. The adenosineA2A receptor is themost abundant adenosine receptor inhumanandmurine BAT.Pharmacological blockade or genetic loss ofA2A receptors inmice causes adecrease inBAT-dependent thermogenesis, whereas treatment with A2A agonists significantly increases energy expenditure. Moreover, pharmacological stimulation of A2A receptors or injection of lentiviral vectors expressing theA 2A receptor into white fat induces brown-like cells-so-called beige adipocytes.Importantly, mice fed a high-fat diet and treated with an A 2A agonist are leaner with improved glucose tolerance. Taken together, our results demonstrate that adenosine-A 2A signalling plays an unexpected physiological role in sympathetic BAT activation and protects mice from diet-induced obesity. Those findings reveal new possibilities for developing novel obesity therapies.
Originalsprog | Engelsk |
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Tidsskrift | Nature |
Vol/bind | 516 |
Udgave nummer | 7531 |
Sider (fra-til) | 395-9 |
Antal sider | 5 |
ISSN | 0028-0836 |
DOI | |
Status | Udgivet - 18 dec. 2014 |