Role of Hypothalamic Foxo1 in the Regulation of Food Intake and Energy Homeostasis

Nat Neurosci. 2006 Jul;9(7):901-6. doi: 10.1038/nn1731. Epub 2006 Jun 18.

Abstract

Insulin signaling in the hypothalamus plays a role in maintaining body weight. Studies suggest that the forkhead transcription factor Foxo1 is an important mediator of insulin signaling in peripheral tissues. Here we demonstrate that in normal mice, hypothalamic Foxo1 expression is reduced by the anorexigenic hormones insulin and leptin. These hormones' effects on feeding are inhibited when hypothalamic Foxo1 is activated, establishing a new signaling pathway through which insulin and leptin regulate food intake in hypothalamic neurons. Moreover, activation of Foxo1 in the hypothalamus increases food intake and body weight, whereas inhibition of Foxo1 decreases both. Foxo1 stimulates the transcription of the orexigenic neuropeptide Y and Agouti-related protein through the phosphatidylinositol-3-kinase (PI3K)/Akt signaling pathway, but suppresses the transcription of anorexigenic proopiomelanocortin by antagonizing the activity of signal transducer-activated transcript-3 (STAT3). Our data suggest that hypothalamic Foxo1 is an important regulator of food intake and energy balance.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • Animals
  • Blotting, Western / methods
  • Body Weight / drug effects
  • Body Weight / physiology
  • Cell Line, Tumor
  • Chromatin Immunoprecipitation / methods
  • Eating / drug effects
  • Eating / physiology*
  • Electrophoretic Mobility Shift Assay / methods
  • Energy Metabolism / drug effects
  • Energy Metabolism / physiology*
  • Forkhead Box Protein O1
  • Forkhead Transcription Factors / physiology*
  • Gene Expression / drug effects
  • Gene Expression / physiology
  • Green Fluorescent Proteins / metabolism
  • Homeostasis / drug effects
  • Homeostasis / physiology*
  • Humans
  • Hypothalamus / drug effects
  • Hypothalamus / metabolism*
  • Immunohistochemistry / methods
  • Insulin / pharmacology
  • Leptin / pharmacology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Neuroblastoma
  • RNA, Small Interfering / pharmacology

Substances

  • Forkhead Box Protein O1
  • Forkhead Transcription Factors
  • Foxo1 protein, mouse
  • Insulin
  • Leptin
  • RNA, Small Interfering
  • Green Fluorescent Proteins