High-fat diet induces apoptosis of hypothalamic neurons

PLoS One. 2009;4(4):e5045. doi: 10.1371/journal.pone.0005045. Epub 2009 Apr 2.

Abstract

Consumption of dietary fats is amongst the most important environmental factors leading to obesity. In rodents, the consumption of fat-rich diets blunts leptin and insulin anorexigenic signaling in the hypothalamus by a mechanism dependent on the in situ activation of inflammation. Since inflammatory signal transduction can lead to the activation of apoptotic signaling pathways, we evaluated the effect of high-fat feeding on the induction of apoptosis of hypothalamic cells. Here, we show that consumption of dietary fats induce apoptosis of neurons and a reduction of synaptic inputs in the arcuate nucleus and lateral hypothalamus. This effect is dependent upon diet composition, and not on caloric intake, since pair-feeding is not sufficient to reduce the expression of apoptotic markers. The presence of an intact TLR4 receptor, protects cells from further apoptotic signals. In diet-induced inflammation of the hypothalamus, TLR4 exerts a dual function, on one side activating pro-inflammatory pathways that play a central role in the development of resistance to leptin and insulin, and on the other side restraining further damage by controlling the apoptotic activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects*
  • Dietary Fats / administration & dosage*
  • Dietary Fats / pharmacology
  • Hypothalamus / cytology
  • Hypothalamus / drug effects*
  • Immunohistochemistry
  • Immunoprecipitation
  • In Situ Nick-End Labeling
  • Male
  • Mice
  • Mice, Inbred C3H
  • Microscopy, Electron, Transmission
  • Neurons / cytology
  • Neurons / drug effects*
  • Polymerase Chain Reaction
  • Rats

Substances

  • Dietary Fats