title: HMG-CoA reductase inhibitor enhances inducible nitric oxide synthase expression in rat vascular smooth muscle cells; involvement of the Rho/Rho kinase pathway.
abstract: Little is known about the mechanism by which HMG-CoA reductase inhibitors affect inducible nitric oxide synthase (iNOS) expression. We investigated the effect of HMG-CoA reductase inhibitor cerivastatin on iNOS expression in cultured rat vascular smooth muscle cells (VSMCs). Quiescent VSMCs were incubated with or without various concentrations of drugs as follows: cerivastatin, C3 exoenzyme or Y-27632. Then, pretreated VSMCs were stimulated by a vehicle or interleukin (IL)-1beta (10 ng/ml). Treatment of VSMCs with cerivastatin (10(-7)-10(-5) mol/l), which inhibits isoprenylation of Rho and other small G proteins, significantly increased nitrite/nitrate (NOx) production and upregulated the expression of iNOS mRNA in IL-1beta-stimulated VSMCs. This effect of cerivastatin was abolished by cotreatment with mevalonate (2x10(-4) mol/l) or geranylgeranyl-pyrophosphate (GGPP) (10(-5) mol/l), but not by farnesyl-pyrophosphate (10(-5) mol/l). Furthermore, C3 exoenzyme (50 microg/ml), an inactivator of Rho protein, and Rho kinase inhibitor Y-27632 (10(-5) mol/l) also enhanced NOx production and the expression of iNOS mRNA in IL-1beta-stimulated VSMCs. Immunocytochemical study revealed that cerivastatin, C3 exoenzyme and Y-27632 did not affect the nuclear translocation of nuclear factor-kappaB in IL-1beta-stimulated VSMCs. Our study suggests that cerivastatin stimulates iNOS expression in IL-1beta treated VSMCs by its inhibitory effect on Rho/Rho kinase pathway. In addition, this effect of cerivastatin, by enhancing iNOS expression, may contribute to the prevention of restenosis after percutaneous coronary intervention and protect against atherothrombosis.
authors.affiliation: Second Department of Medicine, Kyoto Prefectural University of Medicine, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan. teruyama@koto.kpu-m.ac.jp
authors.forename: Teruyuki
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Kazuo
authors.initials: K
authors.lastname: Takeda
authors.forename: Sanae
authors.initials: S
authors.lastname: Harada
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Nakata
authors.forename: Akihiro
authors.initials: A
authors.lastname: Azuma
authors.forename: Susumu
authors.initials: S
authors.lastname: Sasaki
authors.forename: Masao
authors.initials: M
authors.lastname: Nakagawa
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000494:pharmacology*; D007375:Interleukin-1 / Q000494:pharmacology; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D023421:Models, Animal; D008969:Molecular Sequence Data; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects*; D019001:Nitric Oxide Synthase / Q000096:biosynthesis* / Q000187:drug effects*; D052247:Nitric Oxide Synthase Type II; D011336:Probability; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011725:Pyridines / Q000494:pharmacology*; D012333:RNA, Messenger / Q000032:analysis; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D054460:rho-Associated Kinases
chemical_list: D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D007375:Interleukin-1; D047908:Intracellular Signaling Peptides and Proteins; D011725:Pyridines; D012333:RNA, Messenger; C086276:cerivastatin; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases