ab1901

Interactions between human osteoarthritic chondrocytes and synovial fibroblasts in co-culture

K. Huch, J. Stöve, K.P. Günther, W. Puhl

Department of Orthopaedic Surgery, University of Ulm, Ulm, Germany

ABSTRACT
Objective
To imitate the in vivo joint situation and to allow cell interactions, a co-culture system of human osteoarthritic chondrocytes and synovial fibroblasts from a single joint was established and characterized with or without stimulation by IL-1ß.

Methods
Culture settings included chondrocytes in alginate alone, synovial fibroblasts in monolayer alone and a co-culture of both. Proteoglycan (PG) synthesis was measured by 35S-incorporation, PG content by a dimethylmethylene blue assay, DNA content by a fluorometric assay, and prostaglandin-E2 and IL-1ß release by ELISA.

Results
In co-culture PG synthesis by chondrocytes was significantly reduced in the presence of IL-1ß (1 ng/ml) compared to controls. PG content of chondrocyte cultures was reduced for controls and IL-1ß treated co-cultures. Synovial fibroblasts in co-culture did not show significant change of PG synthesis or content when compared to cells in mono-cell culture. PG release into the medium was relatively high in co-cultures. IL-1ß significantly decreased the proliferation rate of chondrocytes in co-cultures and slightly increased prostaglandin-E2 release.

Conclusions
Co-culturing of osteoarthritic chondrocytes and synovial fibroblasts from a single human joint allows interactions between both entities and may offer a useful tool to study the effects of mediators or new drugs under more in vivo like conditions compared to mono-cell cultures.

Key words
Co-culture, chondrocyte, synovial fibroblast, interleukin-1ß.

This work was supported by a grant from the University of Ulm (KH, project P292).
Please address correspondence and reprint requests to: Klaus Huch, MD, Department of Orthopaedic Surgery, University of Ulm, Oberer Eselsberg 45, 89081 Ulm, Germany.
E-mail: klaus.huch@medizin.uni-ulm.de