Phosphatidyl inositol 3-kinase (PI3K) signaling in the hypothalamus has been implicated in the regulation of energy homeostasis, but the critical brain sites where this intracellular signal integrates various metabolic cues to regulate food intake and energy expenditure are unknown. Here, we show that mice with reduced PI3K activity in the ventromedial hypothalamic nucleus (VMH) are more sensitive to high-fat diet-induced obesity due to reduced energy expenditure. In addition, inhibition of PI3K in the VMH impaired the ability to alter energy expenditure in response to acute high-fat diet feeding and food deprivation. Furthermore, the acute anorexigenic effects induced by exogenous leptin were blunted in the mutant mice. Collectively, our results indicate that PI3K activity in VMH neurons plays a physiologically relevant role in the regulation of energy expenditure.
Bibliographical noteFunding Information:
We would like to thank the Mouse Metabolic Phenotyping Core at UTSW Medical Center (supported by NIH PL1 DK081182 and UL1 RR024923). This work was supported by grants from Canadian Institute of Health Research (Y.X.) and the NIH (K99 DK085330 to Y.X.; 1F32DK066972 to J.W.H.; R01DK071051 to B.B.L.; RL1 DK081185, R37DK53301, and R01DK071320 to J.K.E.; and R01CA134502-01 to J.J.Z.); by UTSW Medical Center Disease-Oriented Clinical Scholars Program (J.M.Z.); by the V Foundation (J.J.Z.); by an ADA research grant (1-07-RA-41 to J.K.E. and L.G.); and by an ADA Smith Family Foundation Pinnacle Program Award to J.K.E.
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Cell Biology