High cholesterol diet down regulates the activity of activator protein-1 but not nuclear factor-kappa B in rabbit brain.
Cardiovascular risk factors and alterations in cholesterol metabolism are implicated in the pathogenesis of Alzheimer's dementia (AD). The hypercholesterolemic rabbit model of atheroslerosis and AD was utilized in this study to examine oxidative stress related changes in the brain. The high cholesterol diet induced dramatic increases in plasma and liver cholesterol concentrations, but brain cholesterol levels remained constant. Similar effects have been found regarding lipid oxidation products. The amounts of conjugated dienes, trienes and thiobarbituric acid reactive substances (TBARS) significantly increased in the plasma of cholesterol treated animals while the brain cortex showed no signs of increased lipid peroxidation. The oxidative damage sensitive nuclear transcription factor kappa B (NF-kappaB) and activator protein-1 (AP-1) diverged in their responses. Accordingly, the AP-1 DNA binding activity decreased by more than 50% in brain nuclear protein extracts while the NF-kappaB binding activity remained unaltered by the hypercholesterol diet. These results indicate that despite the relative resistance of the central nervous system to dietary manipulation of its lipid composition and lipid peroxidation products, chronic dietary intake of cholesterol can alter the function of certain proteins involved in regulation of gene expression in the brain.
Kálmán
J
J
Department of Psychiatry, Albert Szent-Gyorgyi University Medical School, Szeged, Hungary. jkalman@nepsy.szote.u.-szeged.hu
Kudchodkar
B J
BJ
Krishnamoorthy
R
R
Dory
L
L
Lacko
A G
AG
Agarwal
N
N
D000818:Animals; D002458:Cell Fractionation; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism*; D002784:Cholesterol / Q000097:blood; D002791:Cholesterol, Dietary / Q000008:administration & dosage*; D004268:DNA-Binding Proteins / Q000378:metabolism; D004036:Diet, Atherogenic; D004195:Disease Models, Animal; D015536:Down-Regulation; D007425:Intracellular Membranes / Q000187:drug effects / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D008099:Liver / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008297:Male; D016328:NF-kappa B / Q000187:drug effects / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism; D009929:Organ Size / Q000187:drug effects; D011817:Rabbits; D018808:Transcription Factor AP-1 / Q000187:drug effects / Q000378:metabolism*
D002791:Cholesterol, Dietary; D004268:DNA-Binding Proteins; D016328:NF-kappa B; D009687:Nuclear Proteins; D018808:Transcription Factor AP-1; D002784:Cholesterol