In vitro activity of anti-rheumatic drugs on release of pro-inflammatory cytokines from oral cells in interaction with microorganisms

Abstract

Periodontitis patients suffering concomitantly from rheumatoid arthritis (RA) often present with less inflamed periodontal tissues due to the ongoing anti-rheumatic therapy. This in vitro study was aimed to analyze whether anti-inflammatory drugs used in the therapy of RA can modulate the release of IL-8 and IL-1β by professional and non-professional immune cells stimulated with microorganisms. Periodontal ligament (PDL) fibroblasts, monocytic MONO-MAC-6-cells, and gingival keratinocytes were exposed to ibuprofen, prednisolone, and methotrexate with and without lysates of Fusobacterium nucleatum or Candida albicans. Supernatants were obtained and the levels of interleukin(IL)-8 and IL-1β (only MONO-MAC-6) were quantified. The addition of F. nucleatum lysate resulted in the strongest release of proinflammatory cytokines by PDL fibroblast and MONO-MAC-6 cells, while the modification by the tested anti-rheumatic drugs was only minor. After stimulation of the MONO-MAC-cells with F. nucleatum, prednisolone increased the release of IL-8, whereas methotrexate decreased the level. Anti-inflammatory drugs increased the adherence of C. albicans to epithelial cells. In patients with RA, the reduction of the microbial load in subgingival biofilm (biofilm removal) is of major importance; however, the intake of inflammatory drugs may interfere with the inflammatory response.

Keywords: anti-inflammatory drugs; oral cells; periodontitis; proinflammatory cytokines; rheumatoid arthritis.

Figure 1

Released interleukin (IL)-8 by monocytic MONO-MAC-6 cells after 18 h of exposure of 20 ng/ml (low), 100 ng/ml (middle), 500 ng/ml (high) prednisolone, 2 μg/ml (low), 10 μg/ml (middle), 50 μg/ml (high) ibuprofen, 1 μg/ml (low), 5 μg/ml (middle), and 25 μg/ml (high) methotrexate (A) w/o microbial compounds, (B) with Fusobacterium nucleatum lysate, and (C) Candida albicans lysate. The columns represent the mean and the bars represent standard deviation. *p < 0.05 vs. control, **p < 0.01 vs. control. ^$$p < 0.01 vs. respective group w/o microbial compounds.

Figure 2

Released interleukin (IL)-1β by monocytic MONO-MAC-6 cells after 18 h of exposure of of 20 ng/ml (low), 100 ng/ml (middle), 500 ng/ml (high) prednisolone, 2 μg/ml (low), 10 μg/ml (middle), 50 μg/ml (high) ibuprofen, 1 μg/ml (low), 5 μg/ml (middle), and 25 μg/ml (high) methotrexate (A) w/o microbial compounds, (B) with Fusobacterium nucleatum lysate, and (C) Candida albicans lysate. The columns represent the mean and the bars represent standard deviation. *p < 0.05 vs. control, **p < 0.01 vs. control. ^$/$$p < 0.05/p < 0.01 vs. respective group w/o microbial compounds.

Figure 3

Released interleukin (IL)-8 by PDL fibroblasts after 18 h of exposure of 20 ng/ml (low), 100 ng/ml (middle), 500 ng/ml (high) prednisolone, 2 μg/ml (low), 10 μg/ml (middle), 50 μg/ml (high) ibuprofen, 1 μg/ml (low), 5 μg/ml (middle), and 25 μg/ml (high) methotrexate (A) w/o microbial compounds, (B) with Fusobacterium nucleatum lysate, and (C) Candida albicans lysate. The columns represent the mean and bars represent standard deviation. ^$/$$p < 0.05/p < 0.01 vs. respective group w/o microbial compound.

Figure 4

Attached (incl. invaded) Candida albicans to TIGK cells (A) and released IL-8 by TIGK cells after 6 h of exposure of 20 ng/ml (low), 100 ng/ml (middle), 500 ng/ml (high) prednisolone, 2 μg/ml (low), 10 μg/ml (middle), 50 μg/ml (high) ibuprofen, 1 μg/ml (low), 5 μg/ml (middle), and 25 μg/ml (high) methotrexate (B) w/o microbial compounds, and with (C) Candida albicans. The columns represent the mean and the bars represent standard deviation. *^/**p < 0.05/p < 0.01 vs. control, ^$/$$p < 0.05/p < 0.01 vs. respective group w/o microbial compound.