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)

In this report an autoradiographic approach is used to compare synthetic activities of cells within differentiated cartilage colonies. While amino acid incorporation is umiform throughout the colony, H-3-uridine is incorporated more actively by cells having little matrix, cells which are typically in the peripheral regions of a colony. On the other hand S-35-O4 is incorporated most actively by cells in the colony centers. This difference in sulfation appears to occur independently of the mitotic state of the cells, since it is apparent in both growing and near-stationary cultures. Instead, there is a correlation between the accumulation of extracellular matrix and more active levels of sulfation. In support of the idea that matrix creates a microenvironment more favorable to chondrogenesis is the observation that a brief treatment with hyaluronidase, which removes about 60% of the S-35-O4 from prelabeled cultures, depresses isolation of labeled glycosaminoglycans. The possible role of extracellular matrices in altering the expression of differentiated functions by creating a more favorable microenvironment is considered.
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PMID:An effect of accumulated matrix on sulfation among cells in a cartilage colony: an autoradiographic study. 16 33

The adherence of group A streptococci to epithelial cells was studied by using streptococcal strains labeled with [(3)H]uridine or fluorescein isothiocyanate. The ability of the labeled organisms to adhere to Detroit 562 epithelial cells, derived from a human pharyngeal carcinoma, as well as to epithelial cells scraped from the oral cavity was determined. Adherence to monolayer cultures or cell suspensions of Detroit cells compared favorably with adherence to suspensions of human oral epithelial cells. Initial experiments to determine the optimal conditions for adherence showed that adherence was temperature dependent and that the optimal incubation time was 15 min for adherence to epithelial cells in suspension and 30 to 60 min for monolayer cultures. Both streptococci and epithelial cells exhibited specificity in the adherence process. Different streptococcal strains varied in their ability to adhere. Adherence was also affected by the growth stage of the bacterial cultures. Trypsin treatment of the streptococci slightly decreased adherence, whereas hyaluronidase treatment increased the adherence of some strains. Streptococci were found to adhere to only about half of the epithelial cells. Those epithelial cells apparently have a limited number of receptor sites since they can be saturated by adding increasing concentrations of bacteria. Further support for limited receptor sites was provided by competition experiments. Adherence was inhibited by trypsin treatment of the epithelial cells, suggesting that proteins in the epithelial cell membrane may play a role in streptococcal adherence.
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PMID:Adherence of group A streptococci to human epithelial cells. 35 28

Corneas from mouse, rat and rabbit were analysed quantitatively and/or qualitatively for collagen and acid glycosaminoglycans. They were examined by light and electron microscopy, using Alcian blue and Cupromeronic blue, in critical electrolyte concentration methods, with or without digestion by hyaluronidase, chondroitinases and keratanase, for their sulphated glycosaminoglycan distributions. Glycosaminoglycan patterns were very different in the three species. Mouse lacked chemically detectable keratan sulphate, which was present in considerable amounts in rat and rabbit stroma. Mouse corneal stroma proteoglycan filaments were located predominantly at the gap zone of the collagen fibrils, mainly at the d band, with few at the a and c bands. Rat and rabbit micrographs were more complicated, with many proteoglycan filaments at the a and c, as well as the d and e bands. These findings support the proposal that the a and c bands were specific binding sites for keratan sulphate proteoglycan (Scott & Haigh, 1985b). Evidence from studies on cornea and cartilage suggests that keratan sulphate, rather than chondroitin sulphate is produced in conditions of O2 lack. Metabolic mechanisms which could account for this balance are proposed The production of uridine diphosphate glucuronic acid is the key step, which is sensitive to hypoxia, lactate and NAD:NADH ratios.
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PMID:Keratan sulphate and the ultrastructure of cornea and cartilage: a 'stand-in' for chondroitin sulphate in conditions of oxygen lack? 297 65

Epithelial endometrial cells were isolated from normal and ovariectomized adult rats. The procedure involves successively (1) perfusion of the uterine vasculature with calcium-free Hanks' solution, (2) perfusion with 0.05% collagenase and 0.1% hyaluronidase in calcium-free Hanks' solution, (3) scraping with a rubber instrument, (4) suspension of detached cells in Eagle's MEM and plating in small plastic containers. 0.5% of freshly isolated cells show typical epithelial morphology. After the 1st day of incubation, epithelial cells present two different forms, flat polygonal cells with dispersed chromatin in the nuclei and large nucleoli, and polyhedral cells grouped in spherical masses whose nuclei are denser and the nucleoli smaller. Both forms possess the typical cytology of epithelial cells in situ. At the 4th day of incubation, mitosis occurs frequently in flat cells, whereas the masses disappear progressively. Proliferating flat cells were cultivated for 15 days without signs of degeneration. Both forms of cells remain metabolically very active as demonstrated by increased 3H-uridine incorporation in response to estradiol-17 beta.
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PMID:A rapid method for the isolation and culture of endometrial epithelial cells responsive to estradiol. 741 89

Sperm adhesion molecule1 (SPAM1), the best characterized hyaluronidase gene, is abundantly expressed in the testis. We attempted to overexpress mouse Spam1 via transgenesis using either the endogenous promoter in a BAC or a heterologous Protamine1 promoter for a Spam1 cDNA transgene. Although transgene-copy numbers ranged from 2 to 15 and transgenic transcripts were expressed, there was a general failure of overexpression of the RNA and protein in the testis of all seven founders. Also, three transgenic lines showed a modest downregulation or co-suppression of the RNA for Spam1 and Hyal5, present on the BAC. We provide evidence for the potential involvement of two co-ordinating post-transcriptional regulatory processes in the failure of overexpression: abundant endogenous antisense RNA and adenosine-uridine (AU)-rich element-mediated regulation of RNA turnover. We demonstrate that AU-rich elements (AREs) in the 3'UTR of mRNAs, well-known to interact with trans-acting proteins to target the RNA for (in)stability, are present in Spam1 RNA and specifically bind to six testicular cytoplasmic proteins. These AU-binding proteins (AUBPs) were virtually absent from the kidney where transcripts are rare, and were shown to interact with the cytoskeleton, which modulates mRNA turnover. In addition to a role in the RNAi pathway, antisense RNA can also modulate ARE-mediated regulation of mRNA by hybridizing to the AREs and specifically silencing their function. This potentially links the two processes in the regulation of Spam1 expression. We hypothesize that testicular Spam1 RNA is regulated post-transcriptionally by cis-acting ARE(s) in the 3'UTR which recognize AUBPs and which are modulated by antisense transcripts.
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PMID:Murine Spam1 mRNA: involvement of AU-rich elements in the 3'UTR and antisense RNA in its tight post-transcriptional regulation in spermatids. 1625 6