Regulação da homeostase energética pelo sistema dopaminérgico no modelo Caenorhabditis elegans

Abstract

The regulation of energy balance, as reflected in fat content, involves an intricate interplay between neural mechanisms that respond to internal and external cues of energy demand and food availability. Compelling data have implicated the neurotransmitter dopamine as an important component of body weight regulation. Overall, the dopaminergic system has been linked to alteration in food seeking and satiety behaviors. However, the precise mechanisms through which dopamine regulates energy homeostasis remain poorly understood. Here, we show that dopamine signaling regulates fat reservoirs in Caenorhabditis elegans. Our analyses revealed that the metabolic modulation could not be accounted for by changes in animal feeding behavior, movement or reproductive rate. Instead, we found that the fat reducing effects of dopamine were dependent on dopaminergic receptors and a set of fat oxidation enzymes. Accordingly, we show that excess dopamine signaling causes increased rates of fat oxidation. Together, our findings reveal an ancient role for dopaminergic regulation of fat and suggest that dopamine signaling elicits this outcome through cascades that, ultimately, mobilizes peripheral fat storage depots.