A comparative analysis of NLRP3-related inflammatory mediators in synovial fluid in temporomandibular joint osteoarthritis and internal derangement

Background The nucleotide-binding oligomerization domain-like receptor pyrin domain containing 3 (NLRP3) inflammasome signaling pathway is a highlighted topic in the field of inflammation. However, there is little research on the relationship between the NLRP3 inflammasome pathway and temporomandibular joint osteoarthritis (TMJOA). The aim of this study was to examine the expression of inflammatory mediators related to the NLRP3 inflammasome in the synovial fluid of patients with condylar cartilage degeneration and verify the clinical effects of sodium hyaluronic acid (HA) treatment on TMJOA. Methods Patients diagnosed with temporomandibular joint internal derangement (TMJID) without condylar defects and TMJOA with condylar defects were divided into two groups. There were thirty patients in each group, and inflammatory mediators related to the NLRP3 inflammasome, including interleukin-1 beta (IL-1 beta), IL-18, NLRP3, and cysteinyl aspartate specific proteinase 1 (CASP1), in synovial fluid were measured by enzyme-linked immunosorbent assay (ELISA). Eighteen patients in the TMJOA group were retested after two HA treatments to evaluate the therapeutic effects of HA. Results IL-1 beta, IL-18, NLRP3 and CASP1 were all positive in the two groups, and TMJOA patients with condylar defects had higher expression of these molecules than TMJID patients (P < 0.05). IL-1 beta, IL-18, and NLRP3 were decreased after two HA treatments (P < 0.05), but there was no significant difference in CASP1 after two HA injections (P=0.549). Conclusions The NLRP3 inflammasome signaling pathway may be involved in condylar degeneration. HA could reduce some inflammatory molecules to alleviate inflammation.