Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.36 (hyaluronidase)
 4,606 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cocultivation of erythroid leukemic cells (ELM-I-1) with hemopoietic supportive cells (MS-5) resulted in a specific adhesion of ELM-I-1 cells to MS-5 cells. This phenomenon was designated as rosette formation. After induction of differentiation of ELM-I-1 cells, rosette formation was reduced, and no rosette formation was observed between erythrocytes and MS-5 cells. Studies on anti-adhesion molecule antibody treatment have revealed that CD44 plays a key role in rosette formation. Expression of CD44 on (the membrane of) ELM-I-1 cells was reduced after differentiation, and no CD44 expression was detected on erythrocytes. CD44 was also expressed on MS-5. Hyaluronate is known as the ligand of CD44, but neither hyaluronidase treatment nor addition of excess hyaluronate to the assay system affected rosette formation. These data indicate that hyaluronate is not responsible for rosette formation. Anti-CD44 antibody (KM81), which recognized the hyaluronate binding site of CD44, inhibited rosette formation. But other monoclonal antibodies against different epitopes except for the hyaluronate binding site, even those against CD44's hyaluronate binding site, did not inhibit rosette formation. Thus, rosette formation between MS-5 cells and ELM-I-1 cells is mediated by CD44 but not by the hyaluronate binding site of CD44.
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PMID:Effects of anti-CD44 monoclonal antibody on adhesion of erythroid leukemic cells (ELM-I-1) to hematopoietic supportive cells (MS-5): CD44, but not hyaluronate-mediated, cell-cell adhesion. 751 42

The role of the adhesion molecule CD44 in the development of NK cells was analyzed in a mouse long-term bone marrow culture system. After 4 wk of culture (day 0), recombinant human IL-2 was added and 13 days later the cells generated were shown to have substantial cytotoxic activity against YAC-1 and to be enriched for NK cells, as assessed for NK-1.1 phenotype by flow cytometric analysis. Physical separation between stroma and precursors partially inhibited proliferation and, consequently, a lower number of cytotoxic cells were produced. Similar results were obtained when an anti-CD44 mAb was added together with IL-2 at day 0. The disruption of hyaluronic acid (HA), one of the ligands of CD44, by hyaluronidase or the competition for the binding of CD44 by soluble HA added with IL-2 on day 0 inhibited both proliferation and development of cytotoxicity to a greater degree than did anti-CD44. These results indicate that interaction of CD44 with HA plays an important role in the development of pre-NK cells into cytotoxic effector cells.
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PMID:Role of CD44 in the development of natural killer cells from precursors in long-term cultures of mouse bone marrow. 751 28

Our previous studies have suggested that the interaction between hyaluronic acid (HA) on peritoneal mesothelial cells and the membrane adhesion molecule, CD44, on ovarian tumour cells could be important in ovarian cancer metastasis. In order to study this further, adhesion of six ovarian tumour lines to HA coated on to a plastic surface was investigated. Four lines bound to the HA coat and two lines did not. The adhesive lines were those that expressed high amounts of CD44, but the degree of adhesion was not closely correlated with CD44 expression. The results suggested that different tumour lines had different affinities for HA. Treatment of the HA coat with hyaluronidase substantially reduced adhesion. Adhesion was also partially reduced if the tumour cells were preincubated with either soluble HA, or anti-CD44 antibodies directed against the HA binding region. An antibody against a non-HA binding region only slightly blocked adhesion at high antibody concentrations. Only the CD44H isoform was detected by immunoprecipitation on the tumour cells. These results suggest that ovarian tumour cells can attach to immobilised HA via CD44H on the cell membrane.
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PMID:Human ovarian tumour cells can bind hyaluronic acid via membrane CD44: a possible step in peritoneal metastasis. 887 6

In previous work, we established the B9/BM1 syngeneic murine bone marrow metastasis model. Interleukin (IL)-6-dependent. IL-1-producing B9/BM1 cells, which colonize the vertebral and femoral marrow after i.v. injection, show great similarity in cell surface phenotype to human myeloma cells, especially the expression of 3 adhesion molecules, CD44, VLA-4 and ICAM-1. Here we investigated the function of these adhesion molecules by binding and transendothelial invasion assays using a newly established bone marrow-derived endothelial cell line (BMEC). A combination of monoclonal antibodies against CD44 and VLA-4 significantly inhibited the adherence of B9/BM1 cells to BMEC and anti-CD44 mAb especially blocked B9/BM1 transendothelial invasion of unstimulated BMEC cells. Results of additional experiments, in which the cells were treated with anti-CD44 and hyaluronidase, demonstrated that the interaction of CD44 molecules on B9/BM1 cells with hyaluronan on BMEC cells was a critical factor in both adhesion and transendothelial invasion in this model. However, stimulation of BMEC with TNFalpha resulted in increased invasion by B9/BM1 cells, which was completely suppressed by anti-VCAM-1 mAb, implicating a significant role of this adhesion molecule in this process during inflammation.
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PMID:Significance of VLA-4-VCAM-1 interaction and CD44 for transendothelial invasion in a bone marrow metastatic myeloma model. 1084 62

Cryptococcus neoformans is a pathogenic yeast that often causes devastating meningoencephalitis in immunocompromised individuals. We have previously identified the C. neoformans CPS1 gene, which is required for a capsular layer on the outer cell wall. In this report, we investigate the function of the CPS1 gene and its pathogenesis. We demonstrated that treatment of yeast with either 4-methylumbelliferone or hyaluronidase resulted in a reduction of the level of C. neoformans binding to human brain microvascular endothelial cells (HBMEC). Yeast extracellular structures were also altered accordingly in hyaluronidase-treated cells. Furthermore, observation of yeast strains with different hyaluronic acid contents showed that the ability to bind to HBMEC is proportional to the hyaluronic acid content. A killing assay with Caenorhabditis elegans demonstrated that the CPS1 wild-type strain is more virulent than the cps1Delta strain. When CPS1 is expressed in Saccharomyces cerevisiae and Escherichia coli, hyaluronic acid can be detected in the cells. Additionally, we determined by fluorophore-assisted carbohydrate electrophoretic analysis that hyaluronic acid is a component of the C. neoformans capsule. The size of hyaluronic acid molecules is evaluated by gel filtration and transmission electron microscopy studies. Together, our results support that C. neoformans CPS1 encodes hyaluronic acid synthase and that its product, hyaluronic acid, plays a role as an adhesion molecule during the association of endothelial cells with yeast.
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PMID:Identification and characterization of CPS1 as a hyaluronic acid synthase contributing to the pathogenesis of Cryptococcus neoformans infection. 1754 16