The brain protein Foxa2 has a key role in regulating food intake, a mouse study in Nature suggests. Strategies that boost brain levels of the protein could improve levels of physical activity and overall health in the population, the authors speculate.
Foxa2 directly regulates expression of two proteins, orexin and melanin-concentrating hormone (MCH) in the lateral hypothalamic area or 'feeding centre' of the brain, Markus Stoffel and colleagues show. After a meal, insulin signalling renders Foxa2 ineffective, and as a result orexin and MCH production ceases.
But mice with Foxa2 permanently switched on express more orexin and MCH, eat more, move more and have increased metabolism and improved insulin sensitivity. And turning Foxa2 on in the brains of obese mice increases lean body mass, reduces fat levels and improves glucose homeostasis. So Foxa2 appears to act as a metabolic sensor in the brain, where it integrates metabolic signals, food-seeking behaviour and physiological responses.
Markus Stoffel (ETH Zurich, Switzerland)
(C) Nature press release.
Message posted by: Trevor M. D'Souza