title: An anti-ulcer drug, geranylgeranylacetone, suppresses inducible nitric oxide synthase in cultured vascular smooth muscle cells.
abstract: OBJECTIVE
  Geranylgeranylacetone (GGA) is commonly used as an anti-ulcer drug. If GGA affects inducible nitric oxide synthase (iNOS) in the vascular tissue, it could influence disease progression in coronary arteries. We investigated the effects of the anti-ulcer drug GGA on iNOS activity in vascular smooth muscle cells.
  
  
  METHODS
  We measured the production of nitrite, a stable metabolite of nitric oxide, in cultured rat vascular smooth muscle cells with the Griess reagent. iNOS protein and mRNA expressions were assayed by western blotting and northern blotting, respectively. The levels of nuclear factor (NF)-kappaB proteins in nuclear extracts were analyzed by gel retardation assay. Heat shock protein 70, a cytoprotective molecule, was evaluated by western blotting.
  
  
  RESULTS
  Incubation of cultures with interleukin-1beta for 24 h caused a significant increase in nitrite generation. Interleukin-1beta-induced nitrite production by vascular smooth muscle cells was significantly suppressed by GGA in a dose-dependent manner. GGA-suppressed nitrite production was accompanied by decreased iNOS mRNA and protein accumulations. GGA by itself did not modulate the basal level of nitrite production. Interleukin-1beta induced NF-kappaB activation in vascular smooth muscle cells, and the addition of GGA further inhibited this NF-kappaB activation. GGA itself induced heat shock protein 70 expression in a dose-dependent manner.
  
  
  CONCLUSIONS
  These findings demonstrated that GGA suppresses iNOS expression in cytokine-stimulated cultured vascular smooth muscle cells partially through the suppression of NF-kappaB activation, suggesting that GGA may modulate the pathophysiology of cardiovascular diseases including atherosclerosis. In addition, this effect may be associated with heat shock protein 70 production by GGA.
authors.affiliation: Division of Cardiovascular Medicine, Jichi Medical School, Tochigi, Japan. kyamamoto@jichi.ac.jp
authors.forename: Keiji
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Mutsuko
authors.initials: M
authors.lastname: Sarukawa
authors.forename: Takayuki
authors.initials: T
authors.lastname: Ito
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Aoki
authors.forename: Masaru
authors.initials: M
authors.lastname: Ichida
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Shimada
mesh_terms: D000818:Animals; D000897:Anti-Ulcer Agents / Q000494:pharmacology; D015152:Blotting, Northern; D015153:Blotting, Western; D002478:Cells, Cultured; D004224:Diterpenes / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D006358:Hot Temperature; D007375:Interleukin-1 / Q000494:pharmacology; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000235:genetics* / Q000378:metabolism; D009573:Nitrites / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
chemical_list: D000897:Anti-Ulcer Agents; D004224:Diterpenes; D018840:HSP70 Heat-Shock Proteins; D007375:Interleukin-1; D016328:NF-kappa B; D009573:Nitrites; D012333:RNA, Messenger; D052247:Nitric Oxide Synthase Type II; C031049:geranylgeranylacetone