Effects of sodium hyaluronate and methylprednisolone acetate on proteoglycan metabolism in equine articular chondrocytes treated with interleukin-1.
OBJECTIVE
To determine the effects of sodium hyaluronate (HA) in combination with methylprednisolone acetate (MPA) on interleukin-1 (IL-1)-induced inflammation in equine articular cartilage pellets.


METHODS
Chondrocytes collected from 7 horses euthanatized for problems unrelated to the musculoskeletal system.


METHODS
Chondrocyte pellets were treated with medium (negative control); medium containing IL-1 (positive control); or medium containing IL-1 with MPA only (0.05 or 0.5 mg/mL), HA only (0.2 or 2 mg/mL), or MPA (0.05 or 0.5 mg/mL) and HA (0.2 or 2 mg/mL) in combination. Proteoglycan (PG) synthesis was determined by incorporation of sulfur 35-labeled sodium sulfate into PGs. Glycosaminoglycan (GAG) content of the media and the pellets and total pellet DNA content were determined.


RESULTS
Methylprednisolone acetate at 0.5 mg/mL caused an increase in PG synthesis, whereas HA had no effect alone. The combination of MPA, both 0.05 mg/mL and 0.5 mg/mL, with HA at 2 mg/mL increased PG synthesis, compared with IL-1-treated control. All treatment groups containing the high concentration of MPA (0.5 mg/mL) and the high concentration of HA (2.0 mg/mL) had pellets with increased GAG content. The addition of HA caused an increase in total GAG content in the media, regardless of MPA treatment. Cyclooxygenase-2 mRNA and aggrecan mRNA expression was significantly reduced with MPA treatment. Total pellet DNA content was unchanged by any treatment.


CONCLUSIONS
Our results indicate that MPA in combination with HA has beneficial effects on PG metabolism of IL-1-treated equine chondrocytes.
Yates
Angela C
AC
Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Urbana, IL 61802.
Stewart
Allison A
AA
Byron
Christopher R
CR
Pondenis
Holly C
HC
Kaufmann
Karissa M
KM
Constable
Peter D
PD
D000276:Adjuvants, Immunologic / Q000008:administration & dosage / Q000494:pharmacology; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000494:pharmacology*; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006736:Horses / Q000378:metabolism*; D006820:Hyaluronic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D007249:Inflammation / Q000188:drug therapy; D007375:Interleukin-1 / Q000633:toxicity; D008775:Methylprednisolone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D000077555:Methylprednisolone Acetate; D011509:Proteoglycans / Q000032:analysis / Q000187:drug effects / Q000378:metabolism*; D013462:Sulfur Radioisotopes / Q000032:analysis
D000276:Adjuvants, Immunologic; D000893:Anti-Inflammatory Agents; D007375:Interleukin-1; D011509:Proteoglycans; D013462:Sulfur Radioisotopes; D000077555:Methylprednisolone Acetate; D006820:Hyaluronic Acid; D008775:Methylprednisolone