Synthesis of a novel thiazolidinedione and evaluation of its modulatory effect on IFN- γ , IL-6, IL-17A, and IL-22 production in PBMCs from rheumatoid arthritis patients

Abstract

Rheumatoid arthritis (RA) is an autoimmune disease frequently characterized by chronic synovitis of multiple joints. The pathogenesis of RA is complex and involves many proinflammatory cytokines as Th17 related ones. PPAR γ is a nuclear receptor activator that represses proinflammatory gene expression. Thus, this work aimed to synthetize a new thiazolidinedione (TZD) analogue based on a well-known anti-inflammatory and PPAR γ agonist activity of this ring and evaluate its anti-inflammatory activity. After chemical structure confirmation, the compound named 5-(5-bromo-2-methoxy-benzylidene)-3-(2-nitro-benzyl)-thiazolidine-2,4-dione TM17 was submitted to cytokine releasing inhibition and PPAR γ genetic modulation assays. The new compound showed no toxicity on human and murine cells, decreasing IL-6 secretion by murine splenocytes and reducing IL-17A, IL-22, and IFN- γ expression in peripheral blood mononuclear cells from patients with RA. TM17 was more efficient in modulating the mRNA expression of PPAR γ than its well-used TZD agonist rosiglitazone. Surprisingly, TM17 was efficient on IL-17A and IFN- γ reduction, like the positive control methylprednisolone, and presented a better effect on IL-22 levels. In conclusion, PBMCs obtained from RA patients under TM17 treatment present a significant reduction in IL-17A, IL-22, and IFN- γ levels, but not IL-6 when compared with nontreated cells, as well as increase PPAR γ mRNA expression in absence of stimulus addressing it as a promising molecule in RA treatment.

Figure 1

(a) Synthetic route for Z-5-(5-bromo-2-metoxy-benzylidene)-3-(2-nitro-benzyl)-thiazolidine-2,4-dione (TM17). (b) Rosiglitazone chemical structure.

Figure 2

Evaluation of proinflammatory cytokines release inhibition by TM17 compound in splenocytes culture. (a) TM17 inhibits the release of IL17A in a dose-dependent manner. (b) IL6 was significantly inhibited by TM17 in all tested doses. (c) TM17 decreases IFNγ release mainly in 10 μM. *P < 0.05.

Figure 3

Evaluation of cytokines release inhibition by TM17 compound in PBMC culture from RA patients. (a) TM17 in 100 μM as well as positive control (methylprednisolone) was able to decrease significantly INF-γ levels. The same pattern was observed for IL17A (b). (c) IL22 was significantly inhibited in all tested concentrations. (d) IL-6 was not significantly inhibited either by TM17 or by methylprednisolone. *P < 0.05,**P < 0.01.

Figure 4

Evaluation of cytokines release inhibition by TM17 compound in PBMC culture from healthly donor. (a) TM17 in 100 μM as well as positive control (methylprednisolone) was able to decrease significantly INF-γ levels. The same pattern was observed for IL-6 (b) and IL-17A (c). *P < 0.05.

Figure 5

PPARγ expression in PBMCs from healthy individuals. (a) PPARy mRNA fold increase in cells treated with rosiglitazone and TM17 compound at 100 μM concentration. (b) Iono and PMA enhance PPARγ expression, and TM17 and rosiglitazone reduce significantly PPARγ mRNA in this condition. *P < 0.05.