Effect of interleukin-1 on the size distribution of cartilage proteoglycans as determined by sedimentation field flow fractionation.
The effect of interleukin-1 (IL-1) on the size distribution of cartilage proteoglycans was studied using sedimentation field flow fractionation (SdFFF), a rapid, high-resolution technique for the separation of proteoglycan monomers and aggregates. During incubation of cartilage in control media, 35S-prelabeled proteoglycan was lost primarily from proteoglycan present in the monomer form; aggregates were conserved. In the presence of IL-1, both 35S-proteoglycan monomers and aggregates were lost, suggesting that IL-1 increases the susceptibility of aggregates to loss from the cartilage matrix. Evaluation of uronic acid as a measure of net change in proteoglycan content indicated that IL-1 causes a net decrease in both monomers and aggregates. Kinetic studies suggested that aggregates are degraded to monomers which then diffuse out of the matrix. Incorporation of [35S]sulfate into cartilage proteoglycans following exposure to IL-1 showed that synthesis of monomers and aggregates is inhibited similarly. SdFFF is a valuable technique for studying proteoglycan metabolism. With its use, changes in proteoglycan monomer and aggregate populations can be detected in response to cytokines such as IL-1.
Arner
E C
EC
Cancer and Inflammatory Diseases Section, E.I. du Pont de Nemours and Company, Wilmington, DE 19880-0400.
Kirkland
J J
JJ
D000818:Animals; D002356:Cartilage / Q000378:metabolism*; D002417:Cattle; D002498:Centrifugation / Q000379:methods; D006801:Humans; D007375:Interleukin-1 / Q000302:isolation & purification / Q000494:pharmacology*; D007700:Kinetics; D046911:Macromolecular Substances; D008970:Molecular Weight; D009000:Monocytes / Q000276:immunology; D011509:Proteoglycans / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism*
D007375:Interleukin-1; D046911:Macromolecular Substances; D011509:Proteoglycans