Atorvastatin inhibition of cytokine-inducible nitric oxide synthase expression in native endothelial cells in situ.
Animal experimental studies have demonstrated that inducible nitric oxide synthase (iNOS) expression correlates with neointima formation and is prevented by HMG-CoA reductase inhibitors (statins). In the present study we have investigated the underlying mechanism of action of these drugs in isolated segments of the rat aorta. Western blot analysis and immunohistochemistry revealed that tumour necrosis factor alpha (TNFalpha) plus interferon-gamma (IFNgamma) synergistically induce iNOS gene expression in the endothelium but not in the smooth muscle of these segments while constitutive endothelial NO synthase (eNOS) abundance was markedly reduced. Pre-treatment with 1 - 10 microM atorvastatin, cerivastatin or pravastatin decreased TNFalpha plus IFNgamma stimulated iNOS expression in the endothelium irrespective of the presence of the HMG-CoA reductase product mevalonate (400 microM). Electrophoretic mobility shift assay experiments confirmed that the combination of TNFalpha plus IFNgamma causes activation of the transcription factors STAT-1 and NF-kappaB in native endothelial cells. Neutralization of these transcription factors by employing the corresponding decoy oligonucleotides confirmed their involvement in TNFalpha plus IFNgamma stimulated iNOS expression. Translocation of both transcription factors was attenuated by atorvastatin, and this effect was insensitive to exogenous mevalonate. The present findings thus demonstrate a specific HMG-CoA reductase-independent inhibitory effect of statins, namely atorvastatin, on cytokine-stimulated transcription factor activation in native endothelial cells in situ and the subsequent expression of a gene product implicated in vascular inflammation. This effect may be therapeutically relevant and in addition provide an explanation for the reported rapid onset of action of these drugs in humans.
Wagner
Andreas H
AH
Department of Cardiovascular Physiology, University of Goettingen School of Medicine, Humboldtallee 23, 37073 Goettingen, Germany.
Schwabe
Oliver
O
Hecker
Markus
M
D000818:Animals; D001013:Aorta, Thoracic / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D000069059:Atorvastatin; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism* / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006538:Heptanoic Acids / Q000494:pharmacology*; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000494:pharmacology*; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000494:pharmacology; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II; D009841:Oligonucleotides / Q000494:pharmacology; D011758:Pyrroles / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D050794:STAT1 Transcription Factor; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D016207:Cytokines; D004268:DNA-Binding Proteins; D006538:Heptanoic Acids; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D016328:NF-kappa B; D009841:Oligonucleotides; D011758:Pyrroles; D050794:STAT1 Transcription Factor; C494081:Stat1 protein, rat; D015534:Trans-Activators; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma; D000069059:Atorvastatin; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat