H. Vondenhoff et al., INTERLEUKIN-1 REVERSIBLY INHIBITS THE SYNTHESIS OF BIGLYCAN AND DECORIN IN INTACT ARTICULAR-CARTILAGE IN CULTURE, Journal of rheumatology, 22(8), 1995, pp. 1520-1526
Objective. To study the effect of interleukin-1 (IL-1) on the synthesi
s of proteoglycans biglycan (DSPG-I) and decorin (DSPG-II) in intact b
ovine articular cartilage. Methods. Cartilage bearing sesamoid bones f
rom the metacarpophalangeal joint were cultured with 10 ng/ml IL-1 for
2 days and labelled with [S-35] sulfate. One sesamoid bone from each
animal had been labelled ex vivo. The remaining 2 were cultured with I
L-1 and allowed to recover in control medium before labelling. Control
cultures were maintained in medium without IL-1 and labelled concurre
ntly with the experimental series. The dermatan sulfate proteoglycans
were purified from 4 M guanidinium chloride extracts of the cartilage
by gel filtration on Sepharose CL-2B and CL-4B, on which they appeared
as a single peak. Biglycan and decorin were separated by sodium dodec
yl sulfide polyacrylamide gel electrophoresis in high salt. Individual
lanes from the gel were cut in slices, which were dissolved and count
ed for radioactivity. Results. Ex vivo, biglycan accounted for 4% and
decorin for 2% of total incorporated sulfate. IL-1 reduced the synthes
is of biglycan to 77% of the level of cultured controls and that of de
corin to 73%. The synthesis of both proteoglycans returned to the cont
rol levels when the IL-1 was removed. IL-1 (10 ng/ml, 2 days) had no s
ignificant effect on total proteoglycan synthesis. Conclusion. The inh
ibition of synthesis of biglycan and decorin by IL-1 might be importan
t in the pathophysiology of cartilage destruction in rheumatic disease
s.