We read with interest the report by Neidal et al on the eVects of methotrexate (MTX) on articular cartilage in vitro and in vivo. The relevance of these findings to patients with rheumatoid arthritis (RA) and other diseases who are receiving MTX is of considerable interest. In a previous study we reported that treatment of RA patients with MTX resulted in reduced numbers of leucocytes and reduc...

We read with interest the report by Neidal et al on the eVects of methotrexate (MTX) on articular cartilage in vitro and in vivo. The relevance of these findings to patients with rheumatoid arthritis (RA) and other diseases who are receiving MTX is of considerable interest. In a previous study we reported that treatment of RA patients with MTX resulted in reduced numbers of leucocytes and reduc...

OBJECTIVE To study the long-term effects of OP-1 on the biosynthesis and proliferation of human articular chondrocytes. METHODS Chondrocytes were released from human cartilage from 10 organ donors of different ages and cultured in alginate. They were exposed to OP-1 (0-200 ng/ml) for 3 to 60 days. Proteoglycan (35S-sulfate) and collagen (3H-proline) synthesis were measured by radiolabeling. P...

Proteoglycans comprise a family of complex macromolecules consisting of a core protein with covalently attached glycosaminoglycan (GAG) chains. The skin anti-aging effects of oral administration of proteoglycan fractions with different molecular weights from salmon nasal cartilage were investigated in a hairless mouse model of skin aging; aging wa...

OBJECTIVE We have shown that copper-oxidized LDL (Ox-LDL) regulates proteoglycan synthesis by arterial smooth muscle cells. Ox-LDL specifically upregulates biglycan expression while causing elongation of glycosaminoglycan chains on all of the major secreted proteoglycans (biglycan, decorin, and versican), resulting in enhanced lipoprotein-binding interactions. It is not known which component of...

The mouse teratocarcinoma-derived cell line, PYS-2, has been shown to produce laminin, a basement membrane-specific glycoprotein. In these studies we demonstrate that PYS-2 cells synthesize and secrete into the culture medium a proteoglycan which contains only heparan sulfate as its sulfated polysaccharide side chains, as well as type IV procollagen and laminin. The apparent molecular weights o...

Reichert's membrane, an extraembryonic membrane present in developing rodents, has been proposed as an in vivo model for the study of basement membranes. We have used this membrane as a source for isolation of basement membrane proteoglycans. Reichert's membranes were extracted in a guanidine/3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate buffer followed by cesium chloride density-gr...

We read with interest the report by Neidal et al on the eVects of methotrexate (MTX) on articular cartilage in vitro and in vivo. The relevance of these findings to patients with rheumatoid arthritis (RA) and other diseases who are receiving MTX is of considerable interest. In a previous study we reported that treatment of RA patients with MTX resulted in reduced numbers of leucocytes and reduc...

The heparan sulfate proteoglycan of the bovine glomerular basement membrane (Mr = 200,000, 30% carbohydrate by weight) has been deglycosylated by various chemical and enzymatic procedures to identify the core protein and provide information about the N- and O-linked saccharide units. Heparitinase digestion of the proteoglycan reduced its Mr to 143,000, consistent with the removal of its four gl...

A technique has been developed for the rapid isolation of proteoglycans from small amounts of tissue extracts using the Beckman Airfuge. Aliquots (50 p1) of proteoglycan samples are layered on preformed CsCl density gradients and centrifuged at -135,000 X g for 4 h. Under both associative and dissociative conditions, proteoglycan sediments to the lower third of the tube (e.g. on a preformed ass...