High concentration simvastatin induces apoptosis in fibroblast-like synoviocytes from patients with rheumatoid arthritis.
OBJECTIVE
We previously reported that 10 mg/day of simvastatin significantly reduced clinical scores of rheumatoid arthritis (RA) in patients with active RA with hypercholesterolemia. We have also reported that a certain pharmacological concentration of simvastatin, i.e., 0.05-0.1 microM, inhibits the production of interleukin 6 (IL-6) and IL-8 and the cell proliferation induced by tumor necrosis factor-alpha (TNF-alpha) in fibroblast-like synoviocytes (FLS) derived from patients with RA in vitro. We investigated other effects of simvastatin on FLS from the standpoint of cell viability and apoptosis.


METHODS
RA FLS were cultured with or without 0.05-50 microM simvastatin for 48 h. Cell viability was determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptosis was measured by flow cytometric analysis using propidium iodide and annexin-V. Caspase-3 and -9 activities were analyzed by colorimetric assays.


RESULTS
High concentrations of simvastatin, i.e., 1.0-50 microM, reduced cell viability and induced prominent apoptosis in FLS in a dose-dependent manner. The apoptosis induced by simvastatin was caspase-3- and caspase-9-dependent. These effects were completely reversed in the presence of mevalonic acid or geranylgeranyl-pyrophosphate, but not in the presence of farnesyl-pyrophosphate. Further, a geranylgeranyl transferase inhibitor and a RhoA kinase inhibitor mimicked the effect of simvastatin.


CONCLUSIONS
These data, together with our previous report, suggest that low (pharmacological range) and high concentrations of simvastatin affect FLS differently: (1) at a low concentration, it inhibits IL-6 and IL-8 production and the cell proliferation of FLS induced by TNF-alpha (2) at high concentrations, it induces apoptosis in FLS. Understanding this dose-dependent biphasic effect of simvastatin may prove important for its clinical applications in the treatment of RA.
Yokota
Kazuhiro
K
Division of Rheumatology and Applied Immunology, Department of Internal Medicine, Saitama Medical University, Saitama, Japan.
Miyoshi
Fumihiko
F
Miyazaki
Takashi
T
Sato
Kojiro
K
Yoshida
Yoshihiro
Y
Asanuma
Yu
Y
Akiyama
Yuji
Y
Mimura
Toshihide
T
D017209:Apoptosis / Q000187:drug effects*; D001172:Arthritis, Rheumatoid / Q000188:drug therapy*; D053148:Caspase 3 / Q000187:drug effects; D053453:Caspase 9 / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D005347:Fibroblasts / Q000187:drug effects*; D005434:Flow Cytometry; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000494:pharmacology*; D015850:Interleukin-6 / Q000378:metabolism; D016209:Interleukin-8 / Q000187:drug effects; D019821:Simvastatin / Q000494:pharmacology*; D013583:Synovial Membrane / Q000166:cytology* / Q000187:drug effects
D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; C508600:IL6 protein, human; D015850:Interleukin-6; D016209:Interleukin-8; D019821:Simvastatin; D053148:Caspase 3; D053453:Caspase 9