Cytokines in temporomandibular joint synovial fluid and tissue in relation to inflammation

Abstract

Background Synovial tissue is known to be the origin of inflammation in joint disease. Despite this, synovial fluid is the main biological specimen of choice in temporomandibular joint (TMJ) inflammation and pathology biomarker research. No comparison of TMJ protein content between synovial fluid and synovial tissue has been made. Objectives The aim of this study was to investigate whether cytokine concentrations in synovial fluid can be related to cytokine concentrations in synovial tissue and to analyse correlation of clinical parameters reflecting local inflammation to cytokine concentrations. Methods Synovial tissue and fluid samples were obtained during the same surgical procedure from a cohort of 101 patients with TMJ disorders. Interleukin (IL) 1β, IL‐6, IL‐8, IL‐10 and tumour necrosis factor α (TNF‐α) were analysed in the samples and an intraindividual correlation made. Various patient‐specific factors related to TMJ inflammation were associated with the cytokine concentrations in synovial fluid and tissue. Results No correlation between cytokine concentration in synovial fluid and synovial tissue was found, except for IL‐8 (ρ = .284, p = .024). Synovial tissue cytokines correlated strongly to inflammation‐related factors: diagnosis (IL‐1β, p = .001; TNF‐α, p = .000; IL‐10, p = .000), TMJ palpation pain (IL‐1β, p = .024; TNF‐α, p = .025), synovitis score (IL‐1β, p = .015) and subjective TMJ pain (TNF‐α, p = .016). Synovial fluid cytokines showed no significant relations to inflammation. Conclusions The investigated cytokine concentrations showed weak correlations between synovial fluid and synovial tissue, besides IL‐8. Synovial tissue appeared to reflect inflammation to a higher extent than synovial fluid. Thus, suggesting that synovial tissue research should complement synovial fluid in future explorations of TMJ pathology and inflammation.

General joint hypermobility in temporomandibular joint disease; clinical characteristics, biomarkers, and surgical aspects

“…A VAS, graded in centimetres, with the endpoints 0 and 10 was used as the assessment instrument. Zero represented no pain/no disability/no psychosocial affection and 10 represented worst imaginable pain/disability/psychosocial affection respectively [ 26 , 27 ].…”

“…Each sample was individually disrupted by grinding in liquid nitrogen. Proteins were extracted from the tissue using an ice-cold NP40 cell lysis buffer (ThermoFisher Scientific) with a ratio of 50 μL buffer per 10 mg of tissue [ 27 , 29 ]. The resulting mixture was centrifuged for 10 min at 20,000 g and 4 °C.…”

Portable Smartphone-Enabled Single-Drop Sensors Based on CsPbX3 (X = Cl, Br) Perovskite Composite Nanofiber Membranes

“…Especially for blood and human tissue fluid, it is natural to take as little as possible, for example just one drop . Facing these problems, it is urgent to develop a portable testing platform that allows common people to detect concentrations in an easy way using smartphones, such as biotin in tissue fluids − and pigments in food, , which may help to avoid subhealth due to the abnormality of these substance concentrations …”

IL-37 counteracts inflammatory injury in the temporomandibular joint via the intracellular pathway

“…The synovial membrane can produce and secrete a variety of nutrients to maintain the viscosity of the synovial fluid, nourish cartilage and protect the bone ( Ulmner et al, 2022 ). However, activated synoviocytes in inflammatory synovitis produce and release a large number of pro-inflammatory factors when synovitis occurs, such as IL-1β, IL-6, MMPs and TNF-α, which mediate cartilage destruction and TMJ inflammation through various ways ( Yuan et al, 2004 ; Sellam and Berenbaum, 2010 ; Jiang et al, 2016 ; Ulmner et al, 2022 ).…”

“…The synovial membrane can produce and secrete a variety of nutrients to maintain the viscosity of the synovial fluid, nourish cartilage and protect the bone ( Ulmner et al, 2022 ). However, activated synoviocytes in inflammatory synovitis produce and release a large number of pro-inflammatory factors when synovitis occurs, such as IL-1β, IL-6, MMPs and TNF-α, which mediate cartilage destruction and TMJ inflammation through various ways ( Yuan et al, 2004 ; Sellam and Berenbaum, 2010 ; Jiang et al, 2016 ; Ulmner et al, 2022 ). Although synovitis is not a prerequisite for the occurrence of TMJOA, more and more studies have indicated that the pro-inflammatory mediators released by synovitis are critical for the occurrence and development of osteoarthritis and the destruction of articular cartilage.…”