RESUMO
OBJECTIVE: To investigate the participation of canonical Wnt and NF-κB signaling pathways in an experimental model of chronic arthritis induced by methylated bovine serum albumin (mBSA) in rat temporomandibular joint (TMJ). MATERIALS AND METHODS: Wistar rats were sensitized by mBSA+Complete Freund Adjuvant (CFA)/Incomplete Freund Adjuvant (IFA) on the first 14 days (1 ×/week). Subsequently, they received 1, 2 or 3 mBSA or saline solution injections into the TMJ (1 ×/week). Hypernociceptive threshold was assessed during the whole experimental period. 24 h after the mBSA injections, the TMJs were removed for histopathological and immunohistochemical analyses for TNF-α, IL-1ß, NF-κB, RANKL, Wnt-10b, ß-catenin and DKK1. RESULTS: The nociceptive threshold was significantly reduced after mBSA injections. An inflammatory infiltrate and thickening of the synovial membrane were observed only after mBSA booster injections. Immunolabeling of TNF-α, IL-1ß and Wnt-10b was increased in the synovial membrane in arthritic groups. The immunoexpression of nuclear ß-catenin was significantly higher only in the group that received 2 booster TMJ injections. However, NF-κB, RANKL and DKK1 immunoexpression were increased only in animals with 3 mBSA intra-articular injections. CONCLUSION: Our results suggest that canonical Wnt and NF-κB signaling pathways participate in the hypernociception and inflammatory response in TMJ synovial membrane during the development of rheumatoid arthritis in rats.
Assuntos
Artrite Experimental/imunologia , Artrite Reumatoide/imunologia , Hiperalgesia/imunologia , NF-kappa B/imunologia , Articulação Temporomandibular/imunologia , Via de Sinalização Wnt , Animais , Artrite Experimental/patologia , Artrite Reumatoide/patologia , Adjuvante de Freund , Hiperalgesia/patologia , Peptídeos e Proteínas de Sinalização Intercelular/imunologia , Interleucina-1beta/imunologia , Lipídeos , Masculino , Ligante RANK/imunologia , Ratos Wistar , Soroalbumina Bovina , Membrana Sinovial/imunologia , Membrana Sinovial/patologia , Articulação Temporomandibular/patologia , Fator de Necrose Tumoral alfa/imunologia , Proteínas Wnt/imunologiaRESUMO
The Wnt signaling pathways play a key role in cell renewal, and there are two such pathways. In patients with rheumatoid arthritis (RA), the synovial membrane expresses genes such as Wnt and Fz at higher levels than those observed in patients without RA. The Wnt proteins are glycoproteins that bind to receptors of the Fz family on the cell surface. The Wnt/Fz complex controls tissue formation during embryogenesis, as well as throughout the process of limb development and joint formation. Recent studies have suggested that this signaling pathway plays a role in the pathophysiology of RA. Greater knowledge of the role of the Wnt signaling pathway in RA could improve understanding of the differences in RA clinical presentation and prognosis. Further studies should also focus on Wnt family members as molecular targets in the treatment of RA.