Tissue and Cell 42 (2010) 151–157
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Tissue and Cell
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Perfusion culture system: Synovial ﬁbroblasts modulate articular chondrocyte
matrix synthesis in vitro
, J. Bruns
, O. Niggemeyer
, M. Fuerst
, W. Rüther
, B. Kurz
Department of Orthopaedics, University Medical Center Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany
Department of Orthopaedics, Klinikum Bad Bramstedt, Oskar-Alexander-Straße 26, D-24576 Bad Bramstedt, Germany
Department of Anatomy, University of Kiel, Otto-Hahn-Platz 8, D-24118 Kiel, Germany
Received 14 May 2009
Received in revised form 21 March 2010
Accepted 22 March 2010
Available online 28 April 2010
Objective: To investigate the interactions of chondrocyte metabolism by synovial cells and synovial super-
natants in a new perfusion co-culture system.
Methods: Chondrocytes and synovial ﬁbroblasts were obtained from knee joints of slaughtered adult cat-
tle. For experimental studies chondrocytes and synovial ﬁbroblasts were placed together into a perfusion
chamber (co-culture) or were placed into two different perfusion culture containers, which were con-
nected by a silicone tube (culturing of chondrocytes with synovial supernatants). A control setup was
used without synovial cells. Chondrocyte proliferation was shown by measurement of DNA content. The
proteoglycan synthesis was quantiﬁed using
-labelling and the dimethylmethylene blue assay.
H-proline incorporation was used to estimate the protein biosynthesis. Type II collagen synthesis was
measured by ELISA, furthermore extracellular matrix deposition was monitored immunohistochemi-
cally (collagen types I/II). Regarding to the role of reactive oxygen species LDH release before and after
stimulation with hydrogen peroxide was measured.
Results: The proliferation of chondrocytes shows an increase in monoculture as well as in co-culture
or in culture with synovial supernatants more than ﬁvefold within 12 days.
as a marker for chondrocytes biosynthetic activity decreases in co-culture system and in culture with
synovial supernatants. A similar effect is seen measuring total proteoglycan content as well as the
incorporation in chondrocytes. Co-culturing and culturing with synovial supernatants lead to a signiﬁcant
decrease of proteoglycan release and content. Quantiﬁcation of collagen type II by ELISA shows signiﬁcant
lower amounts of native collagen type II in the extracellular matrix of co-cultured chondrocytes as well
as in culture with synovial supernatants. The membrane damage of chondrocytes by hydrogen peroxide
is reduced when chondrocytes are co-cultured with synovial ﬁbroblasts.
Conclusion: The co-culture perfusion system is a new tool to investigate interactions of different cell types
with less artiﬁcial interferences. Our results suggest that synovial supernatants and synovial ﬁbroblasts
modulate the biosynthetic activity and the matrix deposition of chondrocytes as well as the susceptibility
to radical attack of reactive oxygen species.
© 2010 Elsevier Ltd. All rights reserved.
The physiological function of synovial joints is based on the
interactions of different connective tissues. Muscle tissue, adi-
pose tissue, ligaments, blood vessels and nerves are components
of synovial joints. However, articular cartilage and synovium are
supposed to be the most important tissues both in physiology and
Corresponding author. Tel.: +49 40 7410 53670; fax: +49 40 7410 55018.
Tel.: +49 40 7410 53670; fax: +49 40 7410 55018.
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pathophysiology. Interactions of chondrocytes and synoviocytes
got into the focus of interest, since it has been shown that nutri-
tion of cartilage in particular is dependent on factors produced by
synoviocytes (Levick and McDonald, 1995). It is also known that
inﬂammatory processes of the synovium are a part of osteoarthri-
tis and rheumatoid arthritis (Katrib et al., 2002). However, little is
currently known about this cellular cross-talk between cartilage
In former investigations synovial supernatants were used to
study the modulation of chondrocyte metabolism in vitro (Lee et al.,
1997), but cellular interactions could not be detected by this experi-
mental setup. Further reports described several other techniques to
culture synoviocytes and chondrocytes together. Nevo et al. (1993)
0040-8166/$ – see front matter © 2010 Elsevier Ltd. All rights reserved.