Effects of interleukin-6 and interleukin-1 beta on expression of growth differentiation factor-5 and Wnt signaling pathway genes in equine chondrocytes

Abstract

Objective—To determine the effects of interleukin (IL)-6 and IL-1β stimulation on expression of growth differentiation factor (GDF)-5 and Wnt signaling pathway genes in equine chondrocytes. Sample—Macroscopically normal articular cartilage samples from 6 horses and osteochondral fragments (OCFs) from 3 horses. Procedures—Chondrocyte pellets were prepared and cultured without stimulation or following stimulation with IL-6 or IL-1β for 1, 2, 12, and 48 hours; expression of GDF-5 was determined with a quantitative real-time PCR assay. Expression of genes in various signaling pathways was determined with microarrays for pellets stimulated for 1 and 2 hours. Immunohistochemical analysis was used to detect GDF-5, glycogen synthase kinase 3β (GSK-3β), and β-catenin proteins in macroscopically normal cartilage samples and OCFs. Results—Chondrocytes stimulated with IL-6 had significantly higher GDF-5 expression within 2 hours versus unstimulated chondrocytes. Microarray analysis of Wnt signaling pathway genes indicated expression of GSK-3β and coiled-coil domain containing 88C increased after 1 hour and expression of β-catenin decreased after 2 hours of IL-6 stimulation. Results of immunohistochemical detection of proteins were similar to microarray analysis results. Chondrocytes in macroscopically normal articular cartilage and OCFs had immunostaining for GDF-5. Conclusion and Clinical Relevance—Results indicated IL-6 stimulation decreased chondrocyte expression of the canonical Wnt signaling pathway transactivator β-catenin, induced expression of inhibitors of the Wnt pathway, and increased expression of GDF-5. This suggested IL-6 may inhibit the Wnt signaling pathway with subsequent upregulation of GDF-5 expression. Anabolic extracellular matrix metabolism in OCFs may be attributable to GDF-5 expression. This information could be useful for development of cartilage repair methods.

Published in

American Journal of Veterinary Research
2014, volume: 75, number: 2, pages: 132-140
Publisher: AMER VETERINARY MEDICAL ASSOC

SLU Authors

• Svala, Emilia

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    

• Ley, Cecilia

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    

• Ekman, Stina

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    

• Skiöldebrand, Eva

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Medicinal Chemistry

Publication identifier

• DOI: https://doi.org/10.2460/ajvr.75.2.132

Permanent link to this page (URI)

https://res.slu.se/id/publ/53586