Molecular aspects in inflammatory events of temporomandibular joint: Microarray-based identification of mediators

Abstract

Synovial inflammation (synovitis) frequently accompanies intracapsular pathologic conditions of the temporomandibular joint (TMJ) such as internal derangement (ID) and/or osteoarthritis (OA), and is suggested to be associated with symptom severity. To identify the putative factors associated with synovitis, we investigated interleukin (IL)-1␤-and/or tumor necrosis factor (TNF)-␣-responsive genes of fibroblast-like synoviocytes (FLS) from patients with ID and/or OA of TMJ using microarray analysis. In this review, we first summarize the FLS of TMJ and the signaling pathways of IL-1␤ and TNF-␣. Next, we show the up-regulated genes in FLS after stimulation with IL-1␤ or TNF-␣, and summarize the gene functions based on recent studies. Among the top 10 up-regulated factors, molecules such as IL-6 and cycrooxygense-2 have been well characterized and investigated in the inflammatory responses and tissue destruction associated with joint diseases such as RA and OA, but the roles of some molecules remain unclear. The FLS reaction can lead to the synthesis and release of a wide variety of inflammatory mediators. Some of these mediators are detected in joint tissues and synovial fluids under intracapsular pathologic conditions, and may represent potential targets for therapeutic interventions in ID and/or OA of TMJ.

Transforming growth factor β activated kinase 1: a potential therapeutic target for rheumatic diseases

“…TRAF2 or TRAF6 undergoes K63 mono-or polyubiquitination in order to execute TAK1 activation at threonine 184/187 residues. This results in downstream phosphorylation of MAPK kinase (MKK) 3/6 and 4/7 to activate p38 and c-Jun N-terminal kinase (JNK) pathways, and inhibitor of nuclear factor-kB (IkB) kinase activation leading to IkBa degradation and nuclear factor-kB (NF-kB) activation [12,17].…”

NFkB and MMP-13 expression in condylar cartilage of temporomandibular joint with occlusal disharmony in vivo

“…The temporomandibular joint (TMJ) is a synovial joint that functions to help the speaking process, opening and closing the mouth, and the process of chewing and swallowing food. 1 Damage to the TMJ is called temporomandibular disorder (TMD). It often occurs without the person realizing it and is assumed to be a common disease that does not require intervention.…”

“…TMD describes a group of common musculoskeletal dysfunctions that affect TMJ or masticatory muscles. 1 The symptoms and signs include such things as clicking sounds and crepitus during the chewing process, which can be followed by joint pain, muscle pain, headache, ear pain, limitation of mandibular movement, deviation and deflection. 1,5 Habitually chewing on one side, bruxism and stress are cause factors of TMJ disorders.…”

“…1 The symptoms and signs include such things as clicking sounds and crepitus during the chewing process, which can be followed by joint pain, muscle pain, headache, ear pain, limitation of mandibular movement, deviation and deflection. 1,5 Habitually chewing on one side, bruxism and stress are cause factors of TMJ disorders. 6 Previous studies have mentioned that occlusal interference also causes TMD, but as yet, no clear understanding of this matter has been arrived at.…”

“…10,11 The over-biomechanical enhancement causes occlusion trauma to periodontal tissue and the TMJ, soft tissue damage, inflammatory reactions and cell damage. 1,11 Cell damage causes the appearance of damage-associated molecular patterns (DAMPS), which will activate the tool-like receptor 4 (TLR-4) in the inflammatory process. TLR4 activation will induce the activation of transcription factors, namely Nuclear Factor Kappa Beta cells (NFκB).…”