A New Pharmacological Effect of Salicylates: Inhibition of NFAT-Dependent Transcription

Abstract

The anti-inflammatory effects of salicylates, originally attributed to inhibition of cyclooxygenase activity, are currently known to involve additional mechanisms. In this study we investigated the possible modulation by salicylates of NFAT-mediated transcription in lymphocytic and monocytic cell lines. RNase protection assays showed that 2-acetoxy-4-trifluoromethylbenzoic acid (triflusal) inhibited, in a dose-dependent manner, mRNA expression of several cytokine genes, most of which are NFAT-regulated and cyclosporin A (CsA)-sensitive. In Jurkat cells, the expression of IL-3, GM-CSF, TNF-α, TGF-β1, IL-2, lymphotactin, MIP-1α, and MIP-1β was inhibited to different extents. In THP-1 cells, inhibition of the expression of M-CSF, G-CSF, stem cell factor, IFN-γ, TNF-α, TGF-β1, lymphotoxin-β1, MIP-1α, MIP-1β, and IL-8 was observed. Sodium salicylate and aspirin only showed significant effects at 5 mM. The transcriptional activity of two genes that contain NFAT sites, a GM-CSF full promoter and a T cell-specific enhancer from the IL-3 locus, was also inhibited by salicylates. Transactivation experiments performed with several NFAT-dependent and AP-1-dependent reporter genes showed that triflusal strongly inhibited NFAT-dependent transcription at concentrations as low as 0.25 mM. Sodium salicylate and aspirin were less potent. The triflusal inhibitory effect was reversible and synergized with suboptimal doses of CsA. Experiments to address the mechanism of action of salicylates in the NFAT activation cascade disclosed a mechanism different from that of CsA, because salicylates inhibited DNA-binding and NFAT-mediated transactivation without affecting phosphorylation or subcellular localization of NFAT. In summary, these data describe a new pharmacological effect of salicylates as inhibitors of NFAT-dependent transcription.

Moxifloxacin enhances antiproliferative and apoptotic effects of etoposide but inhibits its proinflammatory effects in THP-1 and Jurkat cells

“…Our results showed that MXF significantly inhibited the VP-16-enhanced production of IL-8, TNF-a and IL1b in THP-1 cells, but not in Jurkat cells. Accordingly, Aceves et al (2004) reported a different pattern of gene expression in THP-1 and Jurkat cells on their exposure to chemotherapeutic drugs. This may suggest that the inhibitory effect of MXF on the release of proinflammatory cytokines by cells is tumour cell specific.…”

UR-1505, a New Salicylate, Blocks T Cell Activation through Nuclear Factor of Activated T Cells

“…NF-AT may be regulated at different levels: phosphorylation/dephosphorylation, subcellular localization, DNA binding activity, and transactivation (Rao et al, 1997;Aceves et al, 2004). Among these possibilities, our data indicate that UR-1505 acts at the level of DNA binding and/or transactivation, because UR-1505 failed to inhibit NF-AT translocation into the nucleus in response to ionomycin stimulation of HeLa cells.…”

“…Our results are in agreement with previous data reporting that salicylates inhibit cell proliferation through inhibition of Ca 2ϩ /calcineurin/NFAT pathway (Nú ñ ez et al, 2006) because this pathway is activated after TCR engagement. On the other hand, Aceves et al (2004) have shown that salicylates prevent NF-AT-dependent gene expression. Therefore, NF-AT is a target for salicylates and inhibition of NF-AT results in decreased cell proliferation and cytokine production.…”

“…8). Indeed, salicylates are known to not inhibit NF-AT translocation to the nucleus (Aceves et al, 2004).…”

Mannan and peptidoglycan induce COX‐2 protein in human PMN via the mammalian target of rapamycin

“…Of note, the decay of b-actin and GADPH mRNA was also significant in actinomycin D-treated PMN (not shown). Further assessment of transcriptional regulation of COX-2 expression was carried out by looking at the effect of 2-hydroxy-4-trifluoromethylbenzoic acid, an inhibitor of both NF-jB and NF-AT [30,31], which is an useful tool to address in a single-step transcriptional regulation since both transcription factors have been involved in COX-2 regulation in different cell types [32,33]. As shown in Fig.…”