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Molecular Medicine

, Volume 21, Issue 1, pp 726–734 | Cite as

Simvastatin Inhibits Toll-like Receptor 8 (TLR8) Signaling in Primary Human Monocytes and Spontaneous Tumor Necrosis Factor Production from Rheumatoid Synovial Membrane Cultures

  • Lisa Mullen
  • Jason Ferdjani
  • Sandra Sacre
Research Article

Abstract

Simvastatin has been shown to have antiinflammatory effects that are independent of its serum cholesterol lowering action, but the mechanisms by which these antiinflammatory effects are mediated have not been elucidated. To explore the mechanism involved, the effect of simvastatin on toll-like receptor (TLR) signaling in primary human monocytes was investigated. A short pretreatment with simvastatin dose-dependently inhibited the production of tumor necrosis factor (TNF)-α in response to TLR8 activation (but not TLR2, -4 or -5). Statins are known inhibitors of the cholesterol biosynthetic pathway, but, intriguingly, TLR8 inhibition could not be reversed by addition of mevalonate or geranylgeranyl pyrophosphate, downstream products of cholesterol biosynthesis. TLR8 signaling was examined in HEK 293 cells stably expressing TLR8, where simvastatin inhibited I kappa B kinase (IKK)α/β phosphorylation and subsequent nuclear factor (NF)-κB activation without affecting the pathway to activating protein-1 (AP-1). Because simvastatin has been reported to have antiinflammatory effects in RA patients and TLR8 signaling contributes to TNF production in human RA synovial tissue in culture, simvastatin was tested in these cultures. Simvastatin significantly inhibited the spontaneous release of TNF in this model, which was not reversed by mevalonate. Together, these results demonstrate a hitherto unrecognized mechanism of simvastatin inhibition of TLR8 signaling that may in part explain its beneficial antiinflammatory effects.

Notes

Acknowledgments

This work was supported by funding from the European Union Seventh Framework Programme (integrated project Masterswitch; 223404) and by Brighton and Sussex Medical School.

References

  1. 1.
    Choy EH, Panayi GS. (2001) Cytokine pathways and joint inflammation in rheumatoid arthritis. N. Engl. J. Med. 344:907–16.CrossRefGoogle Scholar
  2. 2.
    Chaabo K, Kirkham B. (2015) Rheumatoid arthritis: anti-TNF. Int. Immunopharmacol. 27:180–4.CrossRefGoogle Scholar
  3. 3.
    Gavrila BI, Ciofu C, Stoica V, Panaitescu E. (2015) The efficiency of biologic therapy in a group of patients with rheumatoid arthritis. J. Med. Life. 8:79–84.PubMedPubMedCentralGoogle Scholar
  4. 4.
    Gonzalez-Gay MA, Gonzalez-Juanatey C, Martin J. (2005) Rheumatoid arthritis: a disease associated with accelerated atherogenesis. Semin. Arthritis Rheum. 35:8–17.CrossRefGoogle Scholar
  5. 5.
    Van Doornum S, Jennings GL, Wicks IP. (2006) Reducing the cardiovascular disease burden in rheumatoid arthritis. Med. J. Aust. 184:287–90.PubMedGoogle Scholar
  6. 6.
    Ortego M, et al. (1999) Atorvastatin reduces NF-kappaB activation and chemokine expression in vascular smooth muscle cells and mononuclear cells. Atherosclerosis. 147:253–61.CrossRefGoogle Scholar
  7. 7.
    Zelvyte I, Dominaitiene R, Crisby M, Janciauskiene S. (2002) Modulation of inflammatory mediators and PPARgamma and NFkappaB expression by pravastatin in response to lipoproteins in human monocytes in vitro. Pharmacol. Res. 45:147–54.CrossRefGoogle Scholar
  8. 8.
    Arnaud C, Mach F. (2006) Potential antiinflammatory and immunomodulatory effects of statins in rheumatologic therapy. Arthritis Rheum. 54:390–2.CrossRefGoogle Scholar
  9. 9.
    Costenbader KH, Coblyn JS. (2005) Statin therapy in rheumatoid arthritis. South Med. J. 98:534–540; quiz 541, 572.CrossRefGoogle Scholar
  10. 10.
    Kanda H, et al. (2007) Effects of low-dosage simvastatin on rheumatoid arthritis through reduction of Th1/Th2 and CD4/CD8 ratios. Mod. Rheumatol. 17:364–8.CrossRefGoogle Scholar
  11. 11.
    Tang TT, et al. (2011) Atorvastatin upregulates regulatory T cells and reduces clinical disease activity in patients with rheumatoid arthritis. J. Lipid Res. 52:1023–32.CrossRefGoogle Scholar
  12. 12.
    Leung BP, et al. (2003) A novel anti-inflammatory role for simvastatin in inflammatory arthritis. J. Immunol. 170:1524–30.CrossRefGoogle Scholar
  13. 13.
    Zhang FL, Casey PJ. (1996) Protein prenylation: molecular mechanisms and functional consequences. Annu. Rev. Biochem. 65:241–69.CrossRefGoogle Scholar
  14. 14.
    Falgarone G, Jaen O, Boissier MC. (2005) Role for innate immunity in rheumatoid arthritis. Joint Bone Spine. 72:17–25.CrossRefGoogle Scholar
  15. 15.
    Gierut A, Perlman H, Pope RM. (2010) Innate immunity and rheumatoid arthritis. Rheum. Dis. Clin. North Am. 36:271–96.CrossRefGoogle Scholar
  16. 16.
    Huang QQ, Pope RM. (2009) The role of toll-like receptors in rheumatoid arthritis. Curr. Rheumatol. Rep. 11:357–64.CrossRefGoogle Scholar
  17. 17.
    Wesche H, Henzel WJ, Shillinglaw W, Li S, Cao Z. (1997) MyD88: an adapter that recruits IRAK to the IL-1 receptor complex. Immunity. 7:837–47.CrossRefGoogle Scholar
  18. 18.
    Zhang FX, et al. (1999) Bacterial lipopolysaccharide activates nuclear factor-kappaB through interleukin-1 signaling mediators in cultured human dermal endothelial cells and mononuclear phagocytes. J. Biol. Chem. 274:7611–4.CrossRefGoogle Scholar
  19. 19.
    Fitzgerald KA, et al. (2001) Mal (MyD88-adapter-like) is required for toll-like receptor-4 signal transduction. Nature. 413:78–83.CrossRefGoogle Scholar
  20. 20.
    Yamamoto M, et al. (2002) Cutting edge: a novel Toll/IL-1 receptor domain-containing adapter that preferentially activates the IFN-beta promoter in the toll-like receptor signaling. J. Immunol. 169:6668–72.CrossRefGoogle Scholar
  21. 21.
    Fitzgerald KA, et al. (2003) LPS-TLR4 signaling to IRF-3/7 and NF-kappaB involves the toll adapters TRAM and TRIF. J. Exp. Med. 198:1043–55.CrossRefGoogle Scholar
  22. 22.
    O’Neill LA, Golenbock D, Bowie AG. (2013) The history of toll-like receptors: redefining innate immunity. Nat. Rev. Immunol. 13:453–60.CrossRefGoogle Scholar
  23. 23.
    Lin H, et al. (2011) HMG-CoA reductase inhibitor simvastatin suppresses toll-like receptor 2 ligand-induced activation of nuclear factor kappa B by preventing RhoA activation in monocytes from rheumatoid arthritis patients. Rheumatol. Int. 31:1451–8.CrossRefGoogle Scholar
  24. 24.
    Methe H, Kim JO, Kofler S, Nabauer M, Weis M. (2005) Statins decrease toll-like receptor 4 expression and downstream signaling in human CD14+ monocytes. Arterioscler. Thromb. Vasc. Biol. 25:1439–1445.CrossRefGoogle Scholar
  25. 25.
    Brennan FM, Chantry D, Jackson A, Maini R, Feldmann M. (1989) Inhibitory effect of TNF alpha antibodies on synovial cell interleukin-1 production in rheumatoid arthritis. Lancet. 2:244–7.CrossRefGoogle Scholar
  26. 26.
    Brennan FM, Chantry D, Jackson AM, Maini RN, Feldmann M. (1989) Cytokine production in culture by cells isolated from the synovial membrane. J. Autoimmun. 2 Suppl:177–86.CrossRefGoogle Scholar
  27. 27.
    Menck K, et al. (2014) Isolation of human monocytes by double gradient centrifugation and their differentiation to macrophages in teflon-coated cell culture bags. J. Vis. Exp. e51554.Google Scholar
  28. 28.
    Khoury M, et al. (2007) Inflammation-inducible anti-TNF gene expression mediated by intra-articular injection of serotype 5 adeno-associated virus reduces arthritis. J. Gene Med. 9:596–604.CrossRefGoogle Scholar
  29. 29.
    Chinault SL, et al. (2012) Breast cancer cell targeting by prenylation inhibitors elucidated in living animals with a bioluminescence reporter. Clin. Cancer Res. 18:4136–44.CrossRefGoogle Scholar
  30. 30.
    Mullen LM, Adams G, Chernajovsky Y. (2012) Increased disulphide dimer formation of latent associated peptide fusions of TGF-beta by addition of L-cystine. J. Biotechnol. 161:269–77.CrossRefGoogle Scholar
  31. 31.
    Mosmann T. (1983) Rapid colorimetric assay for cellular growth and survival: application to proliferation and cytotoxicity assays. J. Immunol. Methods. 65:55–63.CrossRefGoogle Scholar
  32. 32.
    Sacre SM, et al. (2008) Inhibitors of TLR8 reduce TNF production from human rheumatoid synovial membrane cultures. J. Immunol. 181:8002–9.CrossRefGoogle Scholar
  33. 33.
    Hilgendorff A, et al. (2003) Statins differ in their ability to block NF-kappaB activation in human blood monocytes. Int. J. Clin. Pharmacol. Ther. 41:397–401.CrossRefGoogle Scholar
  34. 34.
    Liu L, et al. (1999) Integrin-dependent leukocyte adhesion involves geranylgeranylated protein(s). J. Biol. Chem. 274:33334–40.CrossRefGoogle Scholar
  35. 35.
    Yoshida M, et al. (2001) Hmg-CoA reductase inhibitor modulates monocyte-endothelial cell interaction under physiological flow conditions in vitro: involvement of Rho GTPase-dependent mechanism. Arterioscler. Thromb. Vasc. Biol. 21:1165–71.CrossRefGoogle Scholar
  36. 36.
    Guijarro C, et al. (1998) 3-Hydroxy-3-methylglutaryl coenzyme a reductase and isoprenylation inhibitors induce apoptosis of vascular smooth muscle cells in culture. Circ. Res. 83:490–500.CrossRefGoogle Scholar
  37. 37.
    Munro E, et al. (1994) Inhibition of human vascular smooth muscle cell proliferation by lovastatin: the role of isoprenoid intermediates of cholesterol synthesis. Eur. J. Clin. Invest. 24:766–72.CrossRefGoogle Scholar
  38. 38.
    Schonbeck U, Libby P. (2004) Inflammation, immunity, and HMG-CoA reductase inhibitors: statins as antiinflammatory agents? Circulation. 109:II18–26.CrossRefGoogle Scholar
  39. 39.
    Xu H, et al. (2006) RhoA-mediated, tumor necrosis factor alpha-induced activation of NF-kappaB in rheumatoid synoviocytes: inhibitory effect of simvastatin. Arthritis Rheum. 54:3441–51.CrossRefGoogle Scholar
  40. 40.
    Ajibade AA, et al. (2012) TAK1 negatively regulates NF-kappaB and p38 MAP kinase activation in Gr-1+CD11b+ neutrophils. Immunity. 36:43–54.CrossRefGoogle Scholar
  41. 41.
    Qin J, et al. (2006) TLR8-mediated NF-kappaB and JNK activation are TAK1-independent and MEKK3-dependent. J. Biol. Chem. 281:21013–21.CrossRefGoogle Scholar
  42. 42.
    Alzabin S, et al. (2012) Investigation of the role of endosomal toll-like receptors in murine collagen-induced arthritis reveals a potential role for TLR7 in disease maintenance. Arthritis Res. Ther. 14:R142.CrossRefGoogle Scholar
  43. 43.
    Guiducci C, et al. (2013) RNA recognition by human TLR8 can lead to autoimmune inflammation. J. Exp. Med. 210:2903–19.CrossRefGoogle Scholar
  44. 44.
    Kanda H, et al. (2002) Antiinflammatory effect of simvastatin in patients with rheumatoid arthritis. J. Rheumatol. 29:2024–6.PubMedGoogle Scholar
  45. 45.
    Paraskevas KI. (2008) Statin treatment for rheumatoid arthritis: a promising novel indication. Clin. Rheumatol. 27:281–7.CrossRefGoogle Scholar
  46. 46.
    Okamoto H, et al. (2007) Beneficial action of statins in patients with rheumatoid arthritis in a large observational cohort. J. Rheumatol. 34:964–8.PubMedGoogle Scholar
  47. 47.
    Radner H, Aletaha D. (2015) Anti-TNF in rheumatoid arthritis: an overview. Wien. Med. Wochenschr. 165:3–9.CrossRefGoogle Scholar

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Authors and Affiliations

  1. 1.Brighton Musculoskeletal Research Centre and School of Clinical and Laboratory InvestigationBrighton and Sussex Medical School, Trafford CentreBrightonUK

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