AGE

, Volume 35, Issue 5, pp 1589–1606

Citrulline diet supplementation improves specific age-related raft changes in wild-type rodent hippocampus

  • Perrine Marquet-de Rougé
  • Christine Clamagirand
  • Patricia Facchinetti
  • Christiane Rose
  • Françoise Sargueil
  • Chantal Guihenneuc-Jouyaux
  • Luc Cynober
  • Christophe Moinard
  • Bernadette Allinquant
Article

Abstract

The levels of molecules crucial for signal transduction processing change in the brain with aging. Lipid rafts are membrane microdomains involved in cell signaling. We describe here substantial biophysical and biochemical changes occurring within the rafts in hippocampus neurons from aging wild-type rats and mice. Using continuous sucrose density gradients, we observed light-, medium-, and heavy raft subpopulations in young adult rodent hippocampus neurons containing very low levels of amyloid precursor protein (APP) and almost no caveolin-1 (CAV-1). By contrast, old rodents had a homogeneous age-specific high-density caveolar raft subpopulation containing significantly more cholesterol (CHOL), CAV-1, and APP. C99-APP-Cter fragment detection demonstrates that the first step of amyloidogenic APP processing takes place in this caveolar structure during physiological aging of the rat brain. In this age-specific caveolar raft subpopulation, levels of the C99-APP-Cter fragment are exponentially correlated with those of APP, suggesting that high APP concentrations may be associated with a risk of large increases in beta-amyloid peptide levels. Citrulline (an intermediate amino acid of the urea cycle) supplementation in the diet of aged rats for 3 months reduced these age-related hippocampus raft changes, resulting in raft patterns tightly close to those in young animals: CHOL, CAV-1, and APP concentrations were significantly lower and the C99-APP-Cter fragment was less abundant in the heavy raft subpopulation than in controls. Thus, we report substantial changes in raft structures during the aging of rodent hippocampus and describe new and promising areas of investigation concerning the possible protective effect of citrulline on brain function during aging.

Keywords

Aging Amyloid precursor protein Brain Cholesterol Lipid rafts Caveolin-1 Citrulline diet Hippocampus Rodent 

Supplementary material

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High resolution image (TIFF 4355 kb)
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High resolution image (TIFF 1525 kb)

Copyright information

© American Aging Association 2012

Authors and Affiliations

  • Perrine Marquet-de Rougé
    • 2
  • Christine Clamagirand
    • 1
  • Patricia Facchinetti
    • 1
  • Christiane Rose
    • 1
  • Françoise Sargueil
    • 3
  • Chantal Guihenneuc-Jouyaux
    • 4
  • Luc Cynober
    • 2
    • 5
  • Christophe Moinard
    • 2
  • Bernadette Allinquant
    • 1
  1. 1.INSERM UMR 894, Université Paris DescartesSorbonne Paris Cité, Faculté de MédecineParisFrance
  2. 2.EA 4466, Université Paris DescartesSorbonne Paris Cité, Faculté des Sciences Pharmaceutiques et BiologiquesParisFrance
  3. 3.CNRS UMR 5544 and Université Bordeaux 2BordeauxFrance
  4. 4.EA 4064, Université Paris DescartesSorbonne Paris Cité, Faculté des Sciences Pharmaceutiques et BiologiquesParisFrance
  5. 5.Service de Biochimie Hôtel-Dieu et CochinAP-HPParisFrance

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