Cartilage extracellular matrix metabolism differs in serum and synovial fluid.
Most cartilage explant culture studies assume conventional serum-supplemented growth media are biologically equivalent to the natural synovial fluid which baths cartilage in vivo. Few studies have systematically compared the effects of serum versus synovial fluid in culture. To address this assumption we conducted a series of studies to determine if cartilage matrix synthesis is significantly different in serum-based versus synovial fluid-based media. Normal bovine cartilage explants were cultured in DMEM either alone or supplemented with bovine serum or bovine synovial fluid. Matrix synthesis was measured with radiolabeling techniques. We then compared responses to insulin-like growth factor I (IGF-I, a stimulator of matrix synthesis), and interleukin-1beta (IL-1beta, an inhibitor of matrix synthesis). We observed significantly lower matrix synthesis activity in synovial fluid versus serum. Caution shoud be used in extrapolating studies of cartilage grown in media supplemented with serum rather than synovial fluid.
Martin
James A
JA
Ponseti Cell and Molecular Biology Laboratory, Department of Orthopaedic Surgery, The University of Iowa, Iowa City, IA 52242, USA. james-martin@uiowa.edu
Wilkey
Andrew L
AL
Brand
Richard A
RA
D000818:Animals; D001798:Blood Proteins / Q000378:metabolism / Q000494:pharmacology; D002356:Cartilage / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D002417:Cattle; D018929:Cell Culture Techniques / Q000379:methods*; D002478:Cells, Cultured; D003470:Culture Media / Q000737:chemistry / Q000494:pharmacology*; D005109:Extracellular Matrix / Q000187:drug effects / Q000378:metabolism*; D016326:Extracellular Matrix Proteins / Q000096:biosynthesis / Q000187:drug effects; D007334:Insulin-Like Growth Factor I / Q000378:metabolism / Q000494:pharmacology; D007375:Interleukin-1 / Q000378:metabolism / Q000494:pharmacology; D013582:Synovial Fluid / Q000378:metabolism
D001798:Blood Proteins; D003470:Culture Media; D016326:Extracellular Matrix Proteins; D007375:Interleukin-1; D007334:Insulin-Like Growth Factor I