High-fat feeding promotes obesity via insulin receptor/PI3K-dependent inhibition of SF-1 VMH neurons.

Autor: Klöckener T; Department of Mouse Genetics and Metabolism, Institute for Genetics University of Cologne, Köln, Germany., Hess S, Belgardt BF, Paeger L, Verhagen LA, Husch A, Sohn JW, Hampel B, Dhillon H, Zigman JM, Lowell BB, Williams KW, Elmquist JK, Horvath TL, Kloppenburg P, Brüning JC
Jazyk: angličtina
Zdroj: Nature neuroscience [Nat Neurosci] 2011 Jun 05; Vol. 14 (7), pp. 911-8. Date of Electronic Publication: 2011 Jun 05.
DOI: 10.1038/nn.2847
Abstrakt: Steroidogenic factor 1 (SF-1)-expressing neurons of the ventromedial hypothalamus (VMH) control energy homeostasis, but the role of insulin action in these cells remains undefined. We show that insulin activates phosphatidylinositol-3-OH kinase (PI3K) signaling in SF-1 neurons and reduces firing frequency in these cells through activation of K(ATP) channels. These effects were abrogated in mice with insulin receptor deficiency restricted to SF-1 neurons (SF-1(ΔIR) mice). Whereas body weight and glucose homeostasis remained the same in SF-1(ΔIR) mice as in controls under a normal chow diet, they were protected from diet-induced leptin resistance, weight gain, adiposity and impaired glucose tolerance. High-fat feeding activated PI3K signaling in SF-1 neurons of control mice, and this response was attenuated in the VMH of SF-1(ΔIR) mice. Mimicking diet-induced overactivation of PI3K signaling by disruption of the phosphatidylinositol-3,4,5-trisphosphate phosphatase PTEN led to increased body weight and hyperphagia under a normal chow diet. Collectively, our experiments reveal that high-fat diet-induced, insulin-dependent PI3K activation in VMH neurons contributes to obesity development.
Databáze: MEDLINE