The role of Rho-associated kinase in differential regulation by statins of interleukin-1beta- and lipopolysaccharide-mediated nuclear factor kappaB activation and inducible nitric-oxide synthase gene expression in vascular smooth muscle cells.
An optimal level of NO has protective effects in atherosclerosis, whereas large amounts contribute to septic shock. To study how statins, the potent inhibitors of cholesterol synthesis, regulate NO in the vascular wall, we determined their effects on interleukin-1beta (IL-1beta)- and lipopolysaccharide (LPS)-induced NO production in aortic vascular smooth muscle cells (VSMCs). Compared with the large amounts of NO and inducible NO synthase (iNOS) protein expression induced by LPS, the responses of IL-1beta were modest. Various statins were found to inhibit LPS-induced iNOS expression and NO production, although they potentiated IL-1beta responses. In addition, fluvastatin increased IL-1beta-induced p65 nuclear translocation and nuclear factor kappaB (NF-kappaB) activity, although it inhibited those induced by LPS. To address the role of small G proteins in statin's actions, farnesyl transferase inhibitors [alpha-hydroxyfarne-sylphosphonic acid and (2S)-2-[[(2S)-2-[(2S,3S)-2-[(2R)-2-amino-3-mercaptopropyl]amino]-3-methylpentyl]oxy]-1-oxo-3-phenylpropyl]amino]-4-(methylsulfonyl)-butanoic acid 1-methylethyl ester (L-744382)], Rac inhibitor (NSC23766), and Rho-associated kinase (ROCK) inhibitor [N-(4-pyridyl)-4-(1-aminoethyl)cyclohexanecarboxamide dihydrochloride (Y-27632)] were used. We found that Y-27632 potentiated IL-1beta-induced iNOS expression, p65 nuclear translocation, IkappaB kinase (IKK), and NF-kappaB activation, whereas it had minimal effects on LPS-induced responses. In contrast, farnesyl transferase inhibitors blocked iNOS protein expression induced by LPS and IL-1beta, whereas NSC23766 had no effect. Further studies showed that LPS down-regulated Rho and ROCK activity, whereas IL-1beta increased them, suggesting a negative role of Rho and ROCK signaling, which is regulated in contrary manners by IL-1beta and LPS, in IKK/NF-kappaB activation. Through abrogating this negative signaling, statins differentially regulate iNOS expression induced by LPS and IL-1beta in VSMCs. These differential actions of statins on iNOS gene regulation might provide an additional explanation for the pleiotropic beneficial effects of statins.
Wei
Chun-Yu
CY
Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan.
Huang
Kuo-Chin
KC
Chou
Yin-Hsiang
YH
Hsieh
Pe-Fang
PF
Lin
Kuei-Hui
KH
Lin
Wan-Wan
WW
D000577:Amides / Q000494:pharmacology; D000818:Animals; D001011:Aorta / Q000166:cytology / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000494:pharmacology*; D007375:Interleukin-1 / Q000494:pharmacology; D047908:Intracellular Signaling Peptides and Proteins; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D020559:Monomeric GTP-Binding Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D032342:Muscle Cells / Q000187:drug effects / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors / Q000235:genetics*; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000502:physiology*; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D054460:rho-Associated Kinases
D000577:Amides; D004791:Enzyme Inhibitors; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D007375:Interleukin-1; D047908:Intracellular Signaling Peptides and Proteins; D008070:Lipopolysaccharides; D016328:NF-kappa B; D011725:Pyridines; C108830:Y 27632; D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases; D020559:Monomeric GTP-Binding Proteins