title: Immunosuppressants leflunomide and mycophenolic acid inhibit fibroblast IL-6 production by distinct mechanisms.
abstract: Mycophenolic acid (MPA) and A77 1726, the active components of the immunosuppressants mycophenolate mophetil and leflunomide, respectively, in a dose-dependent manner inhibited interferon (IFN)-gamma/LPS-induced interleukin (IL)-6 release in confluent cultures of mouse L929 fibrosarcoma cells. In addition, both drugs markedly reduced the production of the free radical gas nitric oxide (NO), without affecting the viability of L929 cells. The inhibitors of NO synthase, aminoguanidine and L-NMMA, but not L-NMMA inactive counterpart D-NMMA, mimicked the effects of A77 1726 and MPA on IL-6 generation in L929 fibroblasts. Furthermore, NO-releasing substance SNP completely reverted IL-6 accumulation in L929 cultures treated with A77 1726, while only partial recovery of IL-6 production was observed in the presence of MPA. MPA, but not A77 1726, significantly suppressed NO-independent IL-6 release triggered by cAMP-elevating agent rolipram. Thus, while A77 1726 effect on IL-6 production was mediated through concomitant reduction of NO synthesis, MPA action was mainly independent of the interference with NO generation. Finally, both agents inhibited IFN-gamma/LPS-triggered IL-6 production in mouse primary fibroblasts, but not in mouse peritoneal macrophages, indicating cell-specificity of this novel anti-inflammatory action of A77 1726 and MPA.
authors.affiliation: Institute for Biological Research, Belgrade, Yugoslavia.
authors.forename: Dj
authors.initials: Dj
authors.lastname: Miljkovic
authors.forename: T
authors.initials: T
authors.lastname: Samardzic
authors.forename: D
authors.initials: D
authors.lastname: Drakulic
authors.forename: S
authors.initials: S
authors.lastname: Stosic-Grujicic
authors.forename: V
authors.initials: V
authors.lastname: Trajkovic
mesh_terms: D000814:Aniline Compounds / Q000494:pharmacology*; D000818:Animals; D002460:Cell Line; D002470:Cell Survival; D002478:Cells, Cultured; D004396:Coloring Agents / Q000494:pharmacology; D003437:Crotonates; D000242:Cyclic AMP / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D005347:Fibroblasts / Q000378:metabolism*; D006146:Guanidines / Q000378:metabolism; D006801:Humans; D006885:Hydroxybutyrates / Q000494:pharmacology*; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D007371:Interferon-gamma / Q000494:pharmacology; D015850:Interleukin-6 / Q000096:biosynthesis* / Q000378:metabolism; D007555:Isoxazoles / Q000494:pharmacology*; D000077339:Leflunomide; D008264:Macrophages / Q000378:metabolism; D051379:Mice; D009173:Mycophenolic Acid / Q000494:pharmacology*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D009570:Nitriles; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology*; D020889:Rolipram / Q000494:pharmacology; D013778:Tetrazolium Salts / Q000494:pharmacology; D013844:Thiazoles / Q000494:pharmacology; D013997:Time Factors; D014052:Toluidines; D019323:omega-N-Methylarginine / Q000494:pharmacology
chemical_list: D000814:Aniline Compounds; D004396:Coloring Agents; D003437:Crotonates; D004791:Enzyme Inhibitors; D006146:Guanidines; D006885:Hydroxybutyrates; D007166:Immunosuppressive Agents; D015850:Interleukin-6; D007555:Isoxazoles; D009570:Nitriles; D010726:Phosphodiesterase Inhibitors; D013778:Tetrazolium Salts; D013844:Thiazoles; D014052:Toluidines; C527525:teriflunomide; D019323:omega-N-Methylarginine; D007371:Interferon-gamma; D000242:Cyclic AMP; D019001:Nitric Oxide Synthase; C022616:thiazolyl blue; D000077339:Leflunomide; D009173:Mycophenolic Acid; D020889:Rolipram; C004479:pimagedine