β-defensin-3 and β-defensin-4 in synovial fluids from temporomandibular joints with osteoarthrosis

Objective: This study aimed to analyze beta-defensin-3 and beta-defensin-4 in human TMJ synovial fluid obtained from patients affected by osteoarthritis (OA), in order to better understand the pathogenic mechanism that underlies this joint damage. Patients and methods: A total of 28 joints of 21 patients with diagnosis of OA were involved in the study group. Fourteen joints of 10 volunteers without signs or symptoms of TMJ diseases were used as the control group. The synovial fluid samples were collected from the superior joint cavity by the push-and pull method. The supernatant was separated and stored in a deep freezer. The expression of beta-defensin-3 and beta-defensin-4 was evaluated by Western blot analysis. Results: Findings obtained through Western blot showed that with respect to the control, both beta-defensin-3 and beta-defensin-4 were highly expressed (p < 0.01) in OA TMJ synovial fluid; the expression of beta-defensin-3 was very strong, while the beta-defensin-4 was only strongly expressed. In control TMJ synovial fluid the band density observed was strikingly lower with respect to OA TMJ synovial fluid. Conclusions: According to the results obtained, here we hypothesize that (3-defensins augment catabolic pathways in articular cartilage, ultimately leading to a timely breakdown of the extracellular matrix, and they participate in the degeneration of the articular cartilage and bone.