Characterization of newly synthesized proteoglycans from rabbit menisci in organ culture.

Rabbit menisci were incubated with Na2 35SO4 in short-term organ culture to label newly synthesized proteoglycans. The radioactive products present in both tissue and culture medium were characterized separately with respect to distribution after ultracentrifugation in CsCl isopycnic density gradients, hydrodynamic size, interaction with hyaluronic acid, and glycosaminoglycan composition (types, size and content). Analysis of proteoglycan size by gel-filtration chromatography of the most-dense CsCl fractions (A1) on Sephacryl S-500 (associative conditions) resolved three species.

Correlation of histopathology and sulfated proteoglycans in human osteoarthritic hip cartilage.

The histopathologic characteristics, in vitro proteoglycan and glycosaminoglycan biosynthesis, and proteoglycan content of osteoarthritic (OA) cartilage tissue types from human femoral heads obtained at the time of total joint replacement were compared. Articular cartilage from fibrillated or discolored cartilage surfaces demonstrated overlapping histopathologic patterns, while cartilage from osteophytic areas was distinct. 35SO4 from each of these three tissue types was found in two peaks of radioactivity on a Sepharose CL-2B column.

'Gelatinase-like' activity from articular chondrocytes in monolayer culture.

In addition to releasing collagenase and proteoglycanase activity, rabbit articular chondrocytes in monolayer culture released into the culture medium, latent, neutral enzyme activity which when activated by p-aminophenylmercuric acetate degraded fluorescein-labeled polymeric rat tail tendon Type I collagen and the tropocollagen TCA and TCB fragments of human Type II collagen into smaller peptides at 37 degrees C. Enzyme activity was abolished if p-aminophenylmercuric acetate-activated culture medium was preincubated with 1.10-phenanthroline, a metal chelator.

Biosynthesis of proteoglycan in vitro by cartilage from human osteochondrophytic spurs.

Proteoglycan biosynthesis by human osteochondrophytic spurs (osteophytes) obtained from osteoarthritic femoral heads at the time of surgical joint replacement was studied under defined culture conditions in vitro. Osteophytes were primarily present in two anatomic locations, marginal and epi-articular. Minced tissue slices were incubated in the presence of [(35)S]sulphate or [(14)C]glucosamine.