Search

Our objectives were to compare the expression of the hyaluronan receptors CD44 and RHAMM in knee synovial tissue of patients with and without advanced osteoarthritis (OA). Both receptors were detected immunohistochemically; the staining appeared more intense in the tissues from the patients with advanced OA. Expression of CD44 and RHAMM were each significantly increased ( p < 0.05) in synovial tissue from patients with OA, as determined by means of Western-blot analysis. The findings suggested that changes in levels of the HA-binding proteins might be implicated in the development or progression of OA. [ABSTRACT FROM AUTHOR]

The aim of this study was to localise hyaluronan (HA)-binding proteins (HABPs) in ovine vertebral tissues using biotinylated HA oligosaccharides (bHA oligos) as novel affinity probes and to compare this with the distribution of tissue HA visualised using biotinylated aggrecan G1 domain–link protein complex. The bHA oligos, with a size of 6–18 disaccharides were prepared by partial digestion of HA with ovine testicular hyaluronidase, labelled with biotin hydrazide and purified by a combination of aggrecan G1 domain and avidin affinity chromatography. Hyaluronan and HABPs were both prominent pericellular components of hypertrophic cells of the vertebral epiphyseal growth plate and enlarged cells in the cartilaginous end plate of the disc. The bHA oligo probe also visualised HABPs intracellularly in hypertrophic cells, which also contained intracellular HA. Monolayer cultures of ovine annulus fibrosus and nucleus pulposus cells rapidly internalised the bHA oligo affinity probe which was subsequently visualised by indirect fluorescence using avidin-FITC, to cytoplasm and discrete nuclear regions. The results indicate that the abundant pericellular and intracellular HA associated with cartilaginous cells in the vertebral tissues is colocalised with HABPs. The bHA oligo affinity probe may have further applications in investigations of intracellular HABPs, HA endocytosis and the roles they play in cellular regulatory processes. [ABSTRACT FROM AUTHOR]