2026-06-29T07:30:33Zhttps://docta.ucm.es/rest/oai/request

oai:docta.ucm.es:20.500.14352/943162025-03-18T12:48:39Zcom_20.500.14352_14col_20.500.14352_15

Methotrexate limits inflammation through an A20-dependent cross-tolerance mechanism Municio, Cristina Dominguez-Soto, Ángeles Fuentelsaz-Romero, Sara Lamana Domínguez, Amalia Montes, Nuria Cuevas, Víctor García Campos. Raquel Pablos Álvarez, José Luis González-Álvaro, Isidoro Puig-Kröger, Amaya 616.72-002 Reumatología 2302.07 Química Clínica This work was supported by grants from Instituto de Salud Carlos III/FEDER (PI14/00075 and PI17/00037) to AP-K, PI14/00422 to IG-A, RIER RD16 to JLP, IG-A and AP-K, Ministerio de Economía y Competitividad SAF2014-54423-R to ALC. FEDER, Fondo Europeo de Desarrollo Regional: una manera de hacer Europa. SF-R and AP-K are supported by FIBHGM. OBJECTIVES: Methotrexate (MTX) is the anchor drug for treatment of rheumatoid arthritis (RA), but the mechanism of its anti-inflammatory action is not fully understood. In RA, macrophages display a proinflammatory polarisation profile that resembles granulocyte-macrophage colony-stimulating factor (GM-CSF)-differentiated macrophages and the response to MTX is only observed in thymidylate synthase+ GM-CSF-dependent macrophages. To determine the molecular basis for the MTX anti-inflammatory action, we explored toll-like receptor (TLR), RA synovial fluid (RASF) and tumour necrosis factor receptor (TNFR)-initiated signalling in MTX-exposed GM-CSF-primed macrophages. METHODS:Intracellular responses to TLR ligands, TNFα or RASF stimulation in long-term low-dose MTX-exposed human macrophages were determined through quantitative real-time PCR, western blot, ELISA and siRNA-mediated knockdown approaches. The role of MTX in vivo was assessed in patients with arthritis under MTX monotherapy and in a murine sepsis model. RESULTS:MTX conditioned macrophages towards a tolerant state, diminishing interleukin (IL)-6 and IL-1β production in LPS, LTA, TNFα or RASF-challenged macrophages. MTX attenuated LPS-induced MAPK and NF-κB activation, and toll/IL-1R domain-containing adaptor inducing IFN-beta (TRIF1)-dependent signalling. Conversely, MTX increased the expression of the NF-κB suppressor A20 (TNFAIP3), itself a RA-susceptibility gene. Mechanistically, MTX-induced macrophage tolerance was dependent on A20, as siRNA-mediated knockdown of A20 reversed the MTX-induced reduction of IL-6 expression. In vivo, TNFAIP3 expression was significantly higher in peripheral blood cells of MTX-responsive individuals from a cohort of patients with arthritis under MTX monotherapy, whereas MTX-treated mice exhibited reduced inflammatory responses to LPS. CONCLUSIONS:MTX impairs macrophage proinflammatory responses through upregulation of A20 expression. The A20-mediated MTX-induced innate tolerance might limit inflammation in the RA synovial context, and positions A20 as a potential MTX-response biomarker. Instituto de Salud Carlos III European Commission Ministerio de Economía y Competitividad (España) Depto. de Biología Celular Fac. de Ciencias Biológicas TRUE pub 2024-01-22T11:21:04Z 2024-01-22T11:21:04Z 2018 journal article VoR https://hdl.handle.net/20.500.14352/94316 0003-4967 10.1136/annrheumdis-2017-212537 1468-2060 eng Municio C, Dominguez-Soto à , Fuentelsaz-Romero S, et alMethotrexate limits inflammation through an A20-dependent cross-tolerance mechanismAnnals of the Rheumatic Diseases 2018;77:752-759. Attribution-NonCommercial 4.0 International http://creativecommons.org/licenses/by-nc/4.0/ open access application/pdf BMJ Publishing Group