PMCCPMCCPMCC

Search tips
Search criteria 

Advanced

 
Logo of jcinvestThe Journal of Clinical InvestigationCurrent IssueArchiveSubscriptionAbout the Journal
 
J Clin Invest. 1992 December; 90(6): 2268–2277.
PMCID: PMC443378

Studies of the articular cartilage proteoglycan aggrecan in health and osteoarthritis. Evidence for molecular heterogeneity and extensive molecular changes in disease.

Abstract

Changes in the structure of the proteoglycan aggrecan (PG) of articular cartilage were determined immunochemically by RIA and gel chromatography and related to cartilage degeneration documented histologically by the Mankin grading system. Monoclonal antibodies to glycosaminoglycan epitopes were used. In all cartilages, three chondroitin sulfate (CS)-rich populations of large size were observed in addition to a smaller keratan sulfate (KS)-rich population. In grades 7-13 OA cartilages (phase II), molecules were significantly larger than the equivalent molecules of grades 2-6 (phase I). CS chain lengths remained unchanged. In most OA cartilages, a CS epitope 846 was elevated in content, this being most marked in phase II (mean: fivefold). Loss of uronic acid, KS, and hyaluronic acid were only pronounced in phase II OA because of variations in normal contents. Aggregation of PG was unchanged (50-60%) or reduced in OA cartilages, but molecules bearing epitope 846 exhibited almost complete aggregation in normal cartilages. This study provides evidence for the capacity of OA cartilage to synthesize new aggrecan molecules to replace those damaged and lost by disease-related changes. It also defines two phases of PG change in OA: an early predominantly degenerate phase I followed by a net reparative phase II accompanied by net loss of these molecules.

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (1.8M), or click on a page image below to browse page by page.

Images in this article

Click on the image to see a larger version.

Articles from The Journal of Clinical Investigation are provided here courtesy of American Society for Clinical Investigation