Simvastatin inhibits cysteine-rich protein 61 expression in rheumatoid arthritis synovial fibroblasts through the regulation of sirtuin-1/FoxO3a signaling

Arthritis Rheum. 2013 Mar;65(3):639-49. doi: 10.1002/art.37807.


Objective: To examine the role of sirtuin-1 (SIRT-1)/FoxO3a in the expression of cysteine-rich protein 61 (CYR-61) in rheumatoid arthritis synovial fibroblasts (RASFs) and the influence of simvastatin on this pathway, and to determine the relationship between disease progression and FoxO3a/CYR-61 signaling in synovial fibroblasts in vivo using a rat model of collagen-induced arthritis (CIA).

Methods: In RASFs, the expression of CYR-61 and SIRT-1, the localization of FoxO3a in the nucleus/cytoplasm, and the phosphorylation/acetylation of FoxO3a were examined by Western blotting. Secretion of CCL20 was assessed by enzyme-linked immunosorbent assay. Promoter activity of the Cyr61 gene was evaluated by luciferase assay, with or without forced expression of FoxO3a and SIRT-1 by lentiviral transduction. FoxO3a-Cyr61 promoter interaction was examined by chromatin immunoprecipitation. In rats with CIA, the expression of CYR-61 and phosphorylated FoxO3a in synovial fibroblasts was examined by immunohistochemistry.

Results: In RASFs, simvastatin suppressed the tumor necrosis factor α (TNFα)-induced production of CYR-61 and CCL20. Nuclear levels of FoxO3a were decreased after TNFα stimulation of RASFs, and forced expression of FoxO3a reversed the inductive effects of TNFα on CYR-61. Simvastatin inhibited the nuclear export, phosphorylation, and acetylation of FoxO3a and maintained its binding to the Cyr61 promoter. Forced expression of SIRT-1 in RASFs led to decreased levels of CYR-61 and deacetylation of FoxO3a. Following treatment with simvastatin, the expression of SIRT-1 was up-regulated and SIRT-1/FoxO3a binding was enhanced in RASFs. In rats with CIA, intraarticular injection of simvastatin alleviated arthritis and suppressed CYR-61 expression and FoxO3a phosphorylation in synovial fibroblasts.

Conclusion: CYR-61 is important in the pathogenesis of RA, and SIRT-1/FoxO3a signaling is crucial to induction of CYR-61 in RASFs. Simvastatin plays a beneficial role in inflammatory arthritis through its up-regulation of SIRT-1/FoxO3a signaling in synovial fibroblasts. Continued study of the pathways linking sirtuins, FoxO proteins, and the inflammatory responses of RASFs may provide new insights into the pathophysiology of RA.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Arthritis, Experimental / drug therapy
  • Arthritis, Experimental / metabolism
  • Arthritis, Rheumatoid / drug therapy
  • Arthritis, Rheumatoid / metabolism*
  • Cells, Cultured
  • Chemokine CCL20 / metabolism
  • Cysteine-Rich Protein 61 / genetics
  • Cysteine-Rich Protein 61 / metabolism*
  • Disease Models, Animal
  • Fibroblasts / cytology
  • Fibroblasts / drug effects
  • Fibroblasts / metabolism*
  • Forkhead Box Protein O3
  • Forkhead Transcription Factors / metabolism*
  • Humans
  • Hydroxymethylglutaryl-CoA Reductase Inhibitors / pharmacology
  • Male
  • Rats
  • Rats, Sprague-Dawley
  • Signal Transduction / drug effects
  • Signal Transduction / immunology
  • Simvastatin / pharmacology*
  • Sirtuin 1 / metabolism*
  • Synovial Membrane / cytology
  • Synovial Membrane / immunology
  • Tumor Necrosis Factor-alpha / metabolism


  • CCL20 protein, human
  • CCN1 protein, human
  • CCN1 protein, rat
  • Ccl20 protein, rat
  • Chemokine CCL20
  • Cysteine-Rich Protein 61
  • FOXO3 protein, human
  • FOXO3 protein, rat
  • Forkhead Box Protein O3
  • Forkhead Transcription Factors
  • Hydroxymethylglutaryl-CoA Reductase Inhibitors
  • Tumor Necrosis Factor-alpha
  • Simvastatin
  • SIRT1 protein, human
  • Sirt1 protein, rat
  • Sirtuin 1