Significance Of Urokinase-type Plasminogen Activator And Urokinase-type Plasminogen Activator Receptor In Synovial Fluid Of Patients With Temporomandibular Disorders

Temporomandibular disorder(TMD) is a kind of disease which has difficulty in explanation and diagnosis.The present analysis of the joint fluid of temporomandibular joint(TMJ) indicates that the alternation of elements in joint fluid may reflect the degree of lesion of TMJs. Urokinase-type plasminogen activator receptor(uPAR) and its ligand urokinase-type plasminogen activator(uPA) correlates closely to the destruction of articular cartilage and bone, so it becomes a new biological molecular in research of joint diseases.The important role played by the system of plasminogen activator in disease progress of knee joint and hip joint is yet under research, However, whether or not uPA/uPAR in synovial fluid of patients are associated with the development of TMD is yet unclear.Purpose: The study investigated the level of uPA/uPAR concering their relation to progress in patients with TMD, in an attempt to clarify their role in TMD pathogenesis.Methods: Synovial fluid was obtained from 64 TMJs of TMD patients and from 16 TMJs of asymptomatic healthy volunteers as controls. The concentrations of uPA and uPAR in the synovial fluid were measured by an ELISA and correlated with different clinical diagnosis of TMD. According to the standard of diagnosis, the samples from TMD patients are divided into two groups①mild lesion group(n=32);②severe lesion group(n=32). The samples from healthy volunteers is the control group(n=16).Results: Our findings showed that the levels of uPA/uPAR were significantly higher in the synovial fluid of patients than controls (P value＜0.05).Meanwhile, the levels of uPA/uPAR in severe lesion group: (52.85±41.81)pg/ml; (8.65±3.77) pg/ml is significantly higher than that in mild lesion group(14.08±14.24)pg/ml; (3.40±0.92) pg/ml,which is significantly higher than that in control group(0.75±2.52)pgml; (1.03±0.94) pg/ml.(P Values＜0.05)Conclusion:These results suggested that uPA/uPAR in the synovial fluid may participate in the pathogenesis of TMD, and that the lever of uPA/uPAR secreted in TMJ could reflects the pathological degree of TMD as a biochemical markers. Furthermore, this evidence suggests that uPA/uPAR pathway could be one important molecular mechanism in the development of TMD and may represent an important target for TMD treatment.