Disease relevance of Cd44

• Development of a bispecific F(ab')2 conjugate against the complement receptor CR3 of macrophages and a variant CD44 antigen of rat pancreatic adenocarcinoma for redirecting macrophage-mediated tumor cytotoxicity [1].
• The resulting hyaluronic-acid-rich, collagen-poor matrix may enhance infiltration of CD44/hyaluronate-receptor-bearing T-lymphocytes and monocytes into the vascular wall, an early event in atherogenesis [2].

High impact information on Cd44

• RHAMM (Receptor for Hyaluronic Acid Mediated Motility) has been identified as a receptor for the extracellular matrix component hyaluronan (HA) and was recently shown to be essential for the locomotion of normal and transformed peripheral cells [3].
• Glial cells contained 50 and 72 kDa forms of RHAMM, and both of these forms were found to have HA binding capacity [3].
• Here, we report that cultured primary astrocytes, astrocyte cell lines, and microglia express this receptor and exhibit RHAMM-dependent motility [3].
• Time lapse imaging of cell locomotion revealed a significant inhibition of motility and process elongation by neutralizing anti-RHAMM antibodies and by peptides corresponding to the HA binding domains of RHAMM [3].
• The ability of hyaluronic acid to compete with the labelled ligands for binding suggested that the binding site is identical with the recently described hyaluronate receptor on the liver endothelial cells [Smedsrød, Pertoft, Eriksson, Fraser & Laurent (1984) Biochem. J. 223, 617-626] [4].

Biological context of Cd44

• At fixed time-points control and stretch bladders were snap frozen, RNA was extracted, and semiquantitative reverse transcription polymerase chain reaction for collagens I, III and XII, and RHAMM (receptor for hyaluronic acid) messenger (m) RNA was performed to establish trends in stretch related gene expression [5].
• The receptor for hyaluronic acid mediated motility (RHAMM) is a recently described hyaluronic acid binding protein known to influence multiple types of cell extracellular matrix interaction in development, injury and cancer [6].

Anatomical context of Cd44

• Besides, cell activation was still evident 45 days after the silicone injection: activated macrophages exhibited an increased expression of adhesion (CD54 and CD44) and co-stimulatory molecules (CD86) and an enhanced production of oxidant metabolites and NO [7].
• Astrocyte and microglial motility in vitro is functionally dependent on the hyaluronan receptor RHAMM [3].
• Since the receptor directly regulates protein kinase signaling which in turn mediates smooth muscle cell contraction and collagen synthesis, further studies of RHAMM function in bladder pathology are warranted [6].
• RHAMM immunolocalized to the mucosa and detrusor within 2 hours of injury, peaking by 5 to 10 hours [6].
• The hyaluronan receptor RHAMM in noradrenergic fibers contributes to axon growth capacity of locus coeruleus neurons in an intraocular transplant model [8].

Other interactions of Cd44

• Nor could ligands for scavenger receptors and antibodies directed towards ICAM-1, CD 44 and RHAMM (Receptor for HA Mediated Motility) significantly inhibit the association of HA to tumour cells [9].

Analytical, diagnostic and therapeutic context of Cd44

• Tissues were analyzed for temporal and spatial expression of RHAMM in the mucosa and detrusor regions by immunostaining, western and reverse transcriptase polymerase chain reaction analyses [6].
• Immunofluorescence of adult brain sections revealed RHAMM-like immunoreactivity in varicose fibers that were also positive for the noradrenergic marker dopamine-beta-hydroxylase [8].
• By western blotting, anti-RHAMM antibody detected a RHAMM isoform of 75,000 mol. wt in both whole brain homogenate and synaptosome preparations, and a 65,000 mol. wt isoform in synaptosomes [8].
• By comparison of the sequence of this new rat pgp3 cDNA with genomic and cDNA sequences for rat pgp1 and rat pgp2 we selected oligonucleotide probe sequences that would allow us to differentiate between the highly homologous rat pgp2 and pgp3 genes on Northern blots and by polymerase chain reaction (PCR) [10].
• All preparations were subjected to immunocytochemistry for CD44 antigen and Apolipoprotein E (ApoE) [11].

References