Effects of sodium hyaluronate and methylprednisolone acetate on proteoglycan metabolism in equine articular chondrocytes treated with interleukin-1.

The study investigates how sodium hyaluronate (HA) and methylprednisolone acetate (MPA) affect inflammation-induced degradation of articular cartilage in horses. The researchers concluded that MPA and HA combined can positively influence the proteoglycan metabolism in inflamed equine articular chondrocytes.

Methods

• The study uses chondrocyte cells collected from 7 horses that were euthanized due to non-musculoskeletal related problems.
• These chondrocytes were cultured into pellets and subjected to varying treatments. The negative control group was treated with a substance carrier or medium. The positive control was introduced to medium containing inflammatory cytokine interleukin-1 (IL-1).
• The remaining groups were treated with medium containing single or combined doses of MPA and HA. These also had IL-1 to mimic an inflamed environment.
• To measure proteoglycan (PG) synthesis, researchers tracked the incorporation of sulfur 35-labeled sodium sulfate into PGs.
• The glycosaminoglycan (GAG) content was determined in both the culture medium and the cell pellets, and total pellet DNA content was also recorded.

Results

• MPA at a concentration of 0.5 mg/mL enhanced PG synthesis. HA on its own did not have a significant effect on this metric.
• The combined treatment of MPA (at both 0.05 mg/mL and 0.5 mg/mL) with HA at 2 mg/mL increased PG synthesis compared to the IL-1 treated control group.
• All treatment groups that were introduced to the higher concentrations of MPA (0.5 mg/mL) and HA (2.0 mg/mL) had cell pellets with increased GAG content.
• Adding HA to the medium led to an increase in the total GAG content in the medium, irrespective of whether MPA was present.
• Cyclooxygenase-2 mRNA and aggrecan mRNA expression was significantly reduced with MPA treatment.
• Total pellet DNA content did not appear to be significantly affected by any of the treatments.

Conclusions

• The results suggest that the combination of MPA and HA has beneficial effects on the metabolism of proteoglycans in inflamed equine articular chondrocytes, contributing to potential therapeutic applications in managing cartilage-related ailments in horses.