Expression of genes related to oxidative/nitrosative stress in mouse hearts: effect of preconditioning and cholesterol diet.
BACKGROUND
The aim of our study was to explore the effect of high-cholesterol diet and preconditioning on cardiac gene expression patterns in mouse hearts, focusing on genes involved in nitric oxide (NO) and free radical signaling and the mevalonate pathway.


METHODS
Mice were fed 2% high-cholesterol or normal diet for 8 weeks. Hearts isolated from both groups were subjected to either a preconditioning (PC) protocol (3 cycles of 5 min ischemia and 5 min aerobic perfusion) or a time-matched non-preconditioning protocol followed by 30 min global test ischemia and 2 hour reperfusion.


RESULTS
PC altered gene expression only in the mice subjected to a normal diet, as shown in neuronal nitric oxide synthase (nNOS), endothelial nitric oxide synthase (eNOS) and the superoxide-producing enzymes xanthine oxidase (XO) and nicotinamide adenine dinucleotide phosphate (NADPH) oxidases 1 and 4. The rate-limiting enzyme of the mevalonate pathway, 3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase showed differential expression in the myocardium in response to I/R and PC in mice on normal diet but not in cholesterol-fed animals.


CONCLUSIONS
We conclude that cholesterol-enriched diet leads to alterations in preconditioning-induced gene expression in the mouse heart, which might lead to marked changes of oxidative/nitrosative stress signaling and to the attenuation of the cardioprotective effect of preconditioning.
Kocsis
Gabriella F
GF
Department of Biochemistry, University of Szeged, Szeged, Hungary.
Csont
Tamas
T
Varga-Orvos
Zoltan
Z
Puskas
Laszlo G
LG
Murlasits
Zsolt
Z
Ferdinandy
Peter
P
D000704:Analysis of Variance; D000818:Animals; D002791:Cholesterol, Dietary / Q000633:toxicity; D017931:DNA Primers / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D006321:Heart / Q000502:physiology*; D006937:Hypercholesterolemia / Q000378:metabolism*; D019157:Ischemic Preconditioning, Myocardial; D008297:Male; D008798:Mevalonic Acid / Q000378:metabolism; D051379:Mice; D009206:Myocardium / Q000378:metabolism*; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism; D000074624:NADPH Oxidase 1; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000378:metabolism; D018384:Oxidative Stress / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014969:Xanthine Oxidase / Q000378:metabolism
D002791:Cholesterol, Dietary; D017931:DNA Primers; D019001:Nitric Oxide Synthase; D014969:Xanthine Oxidase; D009247:NADH, NADPH Oxidoreductases; D000074624:NADPH Oxidase 1; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases; C422943:Nox4 protein, mouse; D008798:Mevalonic Acid