J. P. Punke¹, R. Y. Au², A. Y. Au², P. V. Phan², S. C. Budsberg¹, C. G. Frondoza².
¹University of Georgia, Athens, GA, United States, ²Nutramax Laboratories, Inc., Edgewood, MD, United States, 3Mississippi State University, Mississippi State, MS, United States, 4Johns Hopkins University, Baltimore, MD, United States

ACVS Abstract 2007

Increasing awareness of the high prevalence of OA in cats has initiated attempts to study the biology of feline articular cartilage. Using cell culture models, we tested the hypothesis that chondrocytes can be activated to produce pro-inflammatory mediators such as prostaglandin E2 (PGE2).

We also tested whether PGE2 is down-regulated by the combination of avocado soybean unsaponifiables (ASU), glucosamine (Glu), and chondroitin sulfate (CS). Feline chondrocytes were propagated in monolayer or in microcarrier spinner cultures. Production of aggrecan and type I and II collagen were determined by immunostaining and Western blot. Cellular morphology was analyzed by phase-contrast microscopy, scanning electron microscopy, and transmission electron microscopy.

For activation analyses, chondrocytes were pre-incubated in monolayer or in microcarrier cultures with control media alone or the combination of ASU, Glu, and CS. Chondrocytes were activated with interleukin-1-beta and tumor necrosis factor-alpha for 24 hours to stimulate PGE2 synthesis. Chondrocytes easily proliferated in monolayer and in microcarrier spinner cultures. Chondrocytes in both culture systems responded to cytokine activation with up to a 5-fold increase in PGE2 synthesis. The response of chondrocytes to activation was down-regulated by 60% with the combination of ASU, Glu, and CS.

The present study demonstrates that feline chondrocytes can be propagated in tissue culture and used as a model to assess functions they perform in native cartilage. Our observation that the combination of ASU, Glu, and CS exerts an anti-inflammatory effect on feline chondrocytes suggests its potential benefit for the management of joint disorders in cats.