Objective
To imitate the in vivo joint situation and to allow cell interactions, a co
-culture system of human human osteoarthritic chondrocytes and synovial fib
roblasts from a single joint was established and characterized with or with
out stimulation by IL-1 beta.
Methods
Culture settings included chondrocytes in alginate alone, synovial fibrobla
sts in monolayer alone and a co-culture of both. Proteoglycan (PG) synthesi
s was measured by S-35-incorporation, PG content by a dimethylmethylene blu
e assay, DNA content by a fluorometric assay, and prostaglandin-E-2 and IL-
1 beta release by ELISA.
Results
In co-culture PG synthesis by chondrocytes was significantly reduced in the
presence of IL-1 beta (1 ng/ml) compared to controls. PG content of chondr
ocyte cultures was reduced for controls and IL-1 beta treated co-cultures.
Synovial fibroblasts in co-culture did not show significant change of PG sy
nthesis or content when compared to cells in mono-cell culture. PG release
into the medium was relatively high in co-cultures. IL-1 beta significantly
deer-eased the proliferation rate of chondrocytes in co-cultures and sligh
tly increased prostaglandin-E-2 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.