Background

Osteoarthritis (OA) is the most common form of degenerative joint diseases and a major cause of disability and impaired quality of life in the elderly.

Aims

This present study investigated the apoptotic factor in synovial fluid obtained from an experimental osteoarthritic (OA) model and examined the major signaling pathways involved in OA cartilage degradation.

Methods

To explore the underlying mechanism, mature beagle dogs underwent a unilateral surgical transection of the cranial cruciate ligament and a medial collateral ligament and medial meniscectomy. The synovial fluid was collected and assay for western blot, lactate dehydrogenase and reactive oxygen species (ROS) were conducted.

Results

Western blot analysis showed that the synovial fluid obtained from osteoarthritis dog showed markedly increased activation of caspase-8 as compared to that of normal. In addition, synovial fluid from osteoarthritis also significantly increased ubiquitin and TRAIL protein expression. Also, osteoarthritis synovial fluid showed high levels of reactive oxygen species (ROS) and increased lactate dehydrogenase (LDH) activity.

Conclusion

Our results suggest that apoptosis may play a pivotal role in osteoarthritis (OA), this apoptotic factor may have a crucial role in cartilage generation and destruction in joint related disease including osteoarthritis. Thus it will be useful for examining the OA pathogens and biomarker to diagnosis.