Taurine chloramine inhibition of cell proliferation and cytokine production by rheumatoid arthritis fibroblast-like synoviocytes

Arthritis Rheum. 1999 Dec;42(12):2552-60. doi: 10.1002/1529-0131(199912)42:12<2552::AID-ANR7>3.0.CO;2-V.

Abstract

Objective: To examine whether taurine (Tau) or its physiologic chlorinated derivative, taurine chloramine (Tau-CI), affects proliferation of, and proinflammatory cytokine (interleukin-6 [IL-6] and IL-8) production by, fibroblast-like synoviocytes (FLS) isolated from rheumatoid arthritis (RA) patients.

Methods: FLS, isolated from the synovial tissue of 19 RA patients and cultured in vitro for 3-6 passages, were stimulated with the recombinant human cytokines IL-1beta (1 ng/ml), tumor necrosis factor alpha (TNFalpha; 10 ng/ml), or IL-17 (10 ng/ml) in the presence of either Tau or Tau-Cl, which were added at concentrations of 50-500 microM. Tau and Tau-Cl were added simultaneously with, 2 hours before, or 24 hours after the stimuli. The concentrations of IL-6 and IL-8 were determined in culture supernatants using specific enzyme-linked immunosorbent assays. Proliferation of FLS was estimated on the basis of 3H-thymidine incorporation into the cells, which were cultured for 72 hours in the presence of recombinant human basic fibroblast growth factor (bFGF) (1 ng/ml) and Tau or Tau-Cl, which were added simultaneously at the beginning of the culture.

Results: Cultured in vitro, RA FLS spontaneously secreted low levels of IL-6 and IL-8, but when RA FLS were stimulated with IL-1beta, TNFalpha, or IL-17, significantly higher amounts of IL-6 and IL-8 were produced. Tau-Cl, but not Tau, inhibited cytokine-triggered synthesis of IL-6 (50% inhibitory concentration [IC50] approximately 225 microM) and IL-8 (IC50 approximately 450 microM) when added simultaneously with the stimuli. However, IL-17-induced production of IL-8 was not affected by Tau-Cl. In the cells prestimulated with IL-1beta for 24 hours, Tau-Cl still inhibited synthesis of IL-6, but did not affect IL-8 production. Moreover, Tau-Cl inhibited spontaneous and bFGF-triggered proliferation of FLS in a dose-dependent manner. Neither Tau nor Tau-Cl affected cell viability.

Conclusion: The results of these studies demonstrate that Tau-Cl inhibits production of proinflammatory cytokines by RA FLS, as well as proliferation of these cells. Thus, Tau-Cl may act as a physiologic modulator of FLS functions related to their pathogenic role in RA.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Arthritis, Rheumatoid / pathology*
  • Cell Division / drug effects
  • Female
  • Fibroblasts / cytology
  • Fibroblasts / drug effects
  • Fibroblasts / metabolism
  • Humans
  • Inflammation Mediators / pharmacology*
  • Interleukin-1 / pharmacology
  • Interleukin-6 / biosynthesis
  • Interleukin-8 / biosynthesis
  • Male
  • Middle Aged
  • Synovial Membrane / cytology*
  • Synovial Membrane / drug effects
  • Synovial Membrane / metabolism
  • Taurine / analogs & derivatives*
  • Taurine / pharmacology
  • Time Factors

Substances

  • Inflammation Mediators
  • Interleukin-1
  • Interleukin-6
  • Interleukin-8
  • Taurine
  • N-chlorotaurine