High Concentration Simvastatin Induces Apoptosis in Fibroblast-like Synoviocytes from Patients with Rheumatoid Arthritis

KAZUHIRO YOKOTA, FUMIHIKO MIYOSHI, TAKASHI MIYAZAKI, KOJIRO SATO, YOSHIHIRO YOSHIDA, YU ASANUMA, YUJI AKIYAMA, and TOSHIHIDE MIMURA

ABSTRACT.

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 µM, inhibits the production of interleukin 6 (IL-6) and IL-8 and the cell proliferation induced by tumor necrosis factor-a (TNF-a) 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 µM 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 µM, 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.

Conclusion. 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-a; (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. (First Release Jan 15 2008; J Rheumatol 2008;35:193-200)

Key Indexing Terms:

RHEUMATOID ARTHRITIS
FIBROBLAST-LIKE SYNOVIOCYTES
CASPASE-3
CASPASE-9
3-HYDROXY-3-METHYLGLUTARYL CO-ENZYME A REDUCTASE INHIBITOR
SMALL G PROTEIN
SIMVASTATIN

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From the Division of Rheumatology and Applied Immunology, Department of Internal Medicine, and the Department of Health Science and Preventive Medicine, Saitama Medical University, Saitama, Japan.

K. Yokota, MD, PhD; F. Miyoshi, PhD; K. Sato, MD, PhD; Y. Yoshida, MD, PhD; Y. Asanuma, MD, PhD; Y. Akiyama, MD, PhD; T. Mimura, MD, PhD, Division of Rheumatology and Applied Immunology, Department of Medicine; T. Miyazaki, PhD, Department of Health Science and Preventive Medicine, Saitama Medical University.

Address reprint requests to Dr. T. Mimura, Division of Rheumatology and Applied Immunology, Department of Medicine, Saitama Medical University, 38 Morohongo, Moroyama-machi, Iruma-gun, Saitama 350-0495, Japan. E-mail: toshim@saitama-med.ac.jp

Accepted for publication October 16, 2007.

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