CD44 is the primary cell surface receptor for the extracellular matrix glycosaminoglycan hyaluronan. Here we determined the relative avidities of unlabeled hyaluronan preparations for cell surface CD44 by their ability to block the binding of fluorescein-conjugated hyaluronan to a variety of cells. We show that hyaluronan binding at the cell surface is a complex interplay of multivalent binding...

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...

We studied the effects of prostaglandin E2 (PGE2) on hyaluronan synthesis in rabbit pericardial mesothelial cells, and the following results were obtained. (1) PGE2 (10-1000 ng/ml) stimulated hyaluronan synthesis and the level of hyaluronan synthase activity in a dose- and time-dependent manner, but PGF2 alpha did not. (2) Cyclic AMP (cAMP) levels in the cells peaked (about a 7-fold increase) a...

Fibrosarcomas are rare malignant mesenchymal tumors originating from fibroblasts. Importantly, fibrosarcoma cells were shown to have a high content and turnover of extracellular matrix (ECM) components including hyaluronan (HA), proteoglycans, collagens, fibronectin, and laminin. ECMs are complicated structures that surround and support cells within tissues. During cancer progression, significa...

Production of the glycosaminoglycan hyaluronan is increased at sites of inflammation, often correlating with the accumulation of leukocytes. Mounting evidence suggests that this polysaccharide can be organized into a wide variety of molecular architectures by its association with specific binding proteins, leading to the formation of fibrils and cable-like structures involving a large number of...

Hyaluronan is a major component of synovial tissue and fluid as well as other soft connective tissues. It is a high-Mr polysaccharide which forms entangled networks already at dilute concentrations (< 1 mg/mL) and endows its solutions with unique rheological properties. Physiological functions of hyaluronan (lubrication, water homeostasis, macromolecular filtering, exclusion, etc.) have been as...

In this report, we describe a novel method for culturing murine trachea epithelial cells on a native basement membrane at an air-liquid interface to produce a pseudostratified, differentiated airway epithelium composed of ciliated and nonciliated cells. This model was used to examine hyaluronan synthesis by the airway epithelial cells (AECs) in response to poly(I,C) and tunicamycin. The former ...

INTRODUCTION Mechanical ventilation with even moderate-sized tidal volumes synergistically increases lung injury in sepsis and has been associated with proinflammatory low-molecular-weight hyaluronan production. High-molecular-weight hyaluronan (HMW HA), in contrast, has been found to be anti-inflammatory. We hypothesized that HMW HA would inhibit lung injury associated with sepsis and mechanic...

BACKGROUND Bupivacaine and supraphysiologic temperature can independently reduce cell viability of articular chondrocytes. In combination, these 2 deleterious factors could further impair cell viability. HYPOTHESIS Hyaluronan may protect chondrocytes from death induced by bupivacaine at supraphysiologic temperatures. STUDY DESIGN Controlled laboratory study. METHODS Bovine articular chond...