Consideration of the role of antigenic keratan sulphate reacting to a 1/14/16H9 antibody as a molecular marker to monitor cartilage metabolism in horses.
The role of keratan sulphate (KS) as a marker of cartilage metabolism was evaluated by using an in vitro model of equine articular cartilage. Articular cartilage was harvested from clinically healthy 6-month-old foals (n=3). Chondrocytes were centrifuged and cultured as pellets. Chondrocyte pellets were stimulated by insulin-like growth factor (IGF)-Ialpha or interleukin (IL)-1alpha for 2 weeks. The sulfated glycosaminoglycans (GAG) and antigenic KS concentrations in the culture media were measured by a 1,9-dimethyl-methylene blue (DMMB) colorimetric assay and an inhibition ELISA using a 1/14/16H9 antibody, respectively. Concentration of GAG was significantly increased in the media of pellets stimulated by both IGF-Ialpha and IL-1alpha. Antigenic KS concentration was significantly increased in those stimulated by IL-1alpha, while no significant change was found in those stimulated by IGF-Ialpha. A high correlation between GAG and antigenic KS concentrations was found in the media of pellets stimulated by IL-1alpha (r=0.87), but not in those stimulated by IGF-Ialpha (r=0.43). The results suggest that the concentration of antigenic KS reacting to 1/14/16H9 mirrors the GAG concentration during the stage of cartilage catabolism, but not during the cartilage anabolic stage. The concentration of antigenic KS reacting to 1/14/16H9 antibody in biological fluids could therefore be a useful marker to further understand principally the catabolic and slightly the anabolic process of articular cartilage metabolism.
Okumura
M
M
Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan.
Tagami
M
M
Fujinaga
T
T
D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism; D015415:Biomarkers; D002358:Cartilage, Articular / Q000187:drug effects / Q000378:metabolism*; D002478:Cells, Cultured; D003470:Culture Media; D006736:Horses / Q000378:metabolism*; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D007375:Interleukin-1 / Q000494:pharmacology; D007632:Keratan Sulfate / Q000276:immunology*
D000911:Antibodies, Monoclonal; D015415:Biomarkers; D003470:Culture Media; D007375:Interleukin-1; D007334:Insulin-Like Growth Factor I; D007632:Keratan Sulfate