OBJECTIVES Whether changes in the hyaluronan moiety of synovial fluid are associated with osteoarthritis (OA) is unresolved experimentally, notwithstanding frequent statements in the literature that the disease leads to degraded hyaluronan. We evaluated this hypothesis by comparing the molecular weight and concentration of hyaluronan in synovial fluid from patients with and without OA. METHOD...

Hyaluronans have been used and studied in horses and humans since the 1970s. Most hyaluronan preparations are a 1% concentration with a molecular size of anywhere between 500,000 and 6,000,000 Daltons. Hyaluronan has been shown to interact with the CD44 receptor to modulate cell proliferation, migration, and gene expression. It has also been shown to decrease proinflammatory mediators and pain-...

The covalent association of inter-alphainhibitor (IαI) derived heavy-chains (HCs) with hyaluronan was first described in synovial fluid from arthritic patients and later described as a structural and functional component of hyaluronan “cable” structures produced by many different cells and stimuli. HC-transfer has been shown to be mediated by the protein product of tumor necrosis factor – stimu...

The catabolic fate of circulating hyaluronan and the proteoglycan chondroitin sulphate (CSPG) was studied in the Atlantic cod (Gadus morhua L.). Distribution studies using radio-iodinated ligand demonstrated that CSPG was rapidly eliminated from the blood by the endocardial endothelial cells (EECs) of the heart atrium and ventricle. The presence of excess amounts of hyaluronan or CSPG inhibited...

The hyaluronan receptor belongs to the polymorphic family of CD44 glycoproteins, which have been implicated in a variety of cellular functions including adhesion to hyaluronan and collagen, the binding of lymphocytes to high endothelial cells during extravasation, and conferring metastatic potential to carcinoma cells. Here, we demonstrate that the receptor also participates in the uptake and d...

Streptococcus pneumoniae hyaluronate lyase (spnHL) is a pathogenic bacterial spreading factor and cleaves hyaluronan, an important constituent of the extra- cellular matrix of connective tissues, through an enzymatic beta-elimination process, different from the hyaluronan degradation by hydrolases in animals. The mechanism of hyaluronan binding and degradation was proposed based on the 1.56 A r...

Hyaluronate lyase enzymes degrade hyaluronan, the main polysaccharide component of the host connective tissues, predominantly into unsaturated disaccharide units, thereby destroying the normal connective tissue structure and exposing the tissue cells to various endo- and exogenous factors, including bacterial toxins. The crystal structures of Streptococcus pneumoniae hyaluronate lyase with tetr...

Hyaluronan (HA) has diverse functions in normal lung homeostasis and pulmonary disease. HA constitutes the major glycosaminoglycan in lung tissue, with HA degradation products, produced by hyaluronidase enzymes and reactive oxygen species, being implicated in several lung diseases, including acute lung injury, asthma, chronic obstructive pulmonary disease, and pulmonary hypertension. The differ...