title: Simvastatin induces apoptosis by a Rho-dependent mechanism in cultured cardiac fibroblasts and myofibroblasts.
abstract: Several clinical trials have shown the beneficial effects of statins in the prevention of coronary heart disease. Additionally, statins promote apoptosis in vascular smooth muscle cells, in renal tubular epithelial cells and also in a variety of cell lines; yet, the effects of statins on cardiac fibroblast and myofibroblast, primarily responsible for cardiac tissue healing are almost unknown. Here, we investigated the effects of simvastatin on cardiac fibroblast and myofibroblast viability and studied the molecular cell death mechanism triggered by simvastatin in both cell types.
  
  
  METHODS
  Rat neonatal cardiac fibroblasts and myofibroblasts were treated with simvastatin (0.1-10μM) up to 72h. Cell viability and apoptosis were evaluated by trypan blue exclusion method and by flow cytometry, respectively. Caspase-3 activation and Rho protein levels and activity were also determined by Western blot and pull-down assay, respectively.
  
  
  RESULTS
  Simvastatin induces caspase-dependent apoptosis of cardiac fibroblasts and myofibroblasts in a concentration- and time-dependent manner, with greater effects on fibroblasts than myofibroblasts. These effects were prevented by mevalonate, farnesylpyrophosphate and geranylgeranylpyrophosphate, but not squalene. These last results suggest that apoptosis was dependent on small GTPases of the Rho family rather than Ras.
  
  
  CONCLUSIONS
  Simvastatin triggered apoptosis of cardiac fibroblasts and myofibroblasts by a mechanism independent of cholesterol synthesis, but dependent of isoprenilation of Rho protein. Additionally, cardiac fibroblasts were more susceptible to simvastatin-induced apoptosis than cardiac myofibroblasts. Thus simvastatin could avoid adverse cardiac remodeling leading to a less fibrotic repair of the damaged tissues.
authors.affiliation: Centro FONDAP Estudios Moleculares de la Célula, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile.
authors.forename: Miguel
authors.initials: M
authors.lastname: Copaja
authors.forename: Daniel
authors.initials: D
authors.lastname: Venegas
authors.forename: Pablo
authors.initials: P
authors.lastname: Aránguiz
authors.forename: Jimena
authors.initials: J
authors.lastname: Canales
authors.forename: Raúl
authors.initials: R
authors.lastname: Vivar
authors.forename: Mabel
authors.initials: M
authors.lastname: Catalán
authors.forename: Ivonne
authors.initials: I
authors.lastname: Olmedo
authors.forename: Andrea E
authors.initials: AE
authors.lastname: Rodríguez
authors.forename: Mario
authors.initials: M
authors.lastname: Chiong
authors.forename: Lisette
authors.initials: L
authors.lastname: Leyton
authors.forename: Sergio
authors.initials: S
authors.lastname: Lavandero
authors.forename: Guillermo
authors.initials: G
authors.lastname: Díaz-Araya
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001549:Benzamides / Q000494:pharmacology; D020169:Caspases / Q000502:physiology; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002784:Cholesterol / Q000096:biosynthesis; D005347:Fibroblasts / Q000187:drug effects* / Q000502:physiology; D006321:Heart / Q000187:drug effects*; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000494:pharmacology*; D008715:Methionine / Q000031:analogs & derivatives / Q000494:pharmacology; D058628:Myofibroblasts / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D019821:Simvastatin / Q000494:pharmacology*; D020742:rhoA GTP-Binding Protein / Q000502:physiology*
chemical_list: D001549:Benzamides; C404062:FTI 276; C102521:GGTI 298; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D002784:Cholesterol; D008715:Methionine; D019821:Simvastatin; D020169:Caspases; D020742:rhoA GTP-Binding Protein