Activation of human synovial cells by cholera enterotoxin: correlation of morphological responses with adenylate cyclase activities, and the reversing effects of hyaluronidase

Does hyaluronan have a role in endothelial cell proliferation of the synovium?

Hyaluranate (HA) is a major constituent of synovial fluid, but its concentration and molecular size differ in normal and inflamed joints. HA can induce or inhibit angiogenesis depending on both its size and its concentration. Endothelial-cell endocytose-labeled macromolecular HA and HA oligosaccharides and binding studies have identified an HA-specific receptor on the endothelial cell surface (KD, 10(-10) mol/L; approximately 2,000/cell). The molecular weight of HA-binding proteins was found to be 90 to 125, 78, and 46 kd.

Effect of the microbial constituents, LPS and BCG, on the glycosaminoglycans of chondrocyte cultures

Earlier we reported that articular chondrocytes in monolayer culture produce pericellular proteoglycans both with short and long half lives, T-1 and T-2 (Kittlick et al. 1991 b). Now monolayer cultures have been investigated to assess the influence on the metabolism of pericellular proteoglycans or glycosaminoglycans by lipopolysaccharide of E. coli and S. typhimurium as well as by Bacillus Calmette-Guérin.

Hyaluronic acid production in vitro by synovial lining cells from normal and rheumatoid joints

Organ cultures and primary cell cultures were established from synovial tissue collected from patients with rheumatoid arthritis. Hyaluronic acid measured by the incorporation of [3H]glucosamine into the polysaccharide was found to be synthesised in the cultures immediately after transfer from in-vivo to in-vitro conditions. This was in contrast to the primary cultures established from cells isolated from normal joints. The latter cells did not synthesise any detectable hyaluronate. 90-100% of the cells in primary culture were found to be esterase positive, indicating their macrophage nature. The molecular weight of the hyaluronate produced by the pathological cells was low (approximately 50 000) compared with the molecular weight of hyaluronate found in joint fluid from normal or rheumatoid joints. Cell lines of fibroblasts established from rheumatoid joints and studied after four or seven passages also produced hyaluronate of low molecular weight. It is known that similar cell lines from normal joints produce a high molecular weight polymer.