Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.2.1.31 (beta-glucuronidase)
7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have studied the role of arachidonic acid (AA) metabolism in the release of lysosomal enzymes (beta-glucuronidase and lysozyme) from human polymorphonuclear leukocytes (PMNs). 5,8,11,14-Eicosatetraenoic acid (ETYA), which inhibits both the cyclo-oxygenase and the lipoxygenase pathways of AA metabolism, was found to cause a dose-dependent inhibition of lysosomal enzyme release from human PMNs induced by immunological (i.e., serum-treated zymosan: Zx) and nonimmunological stimuli (i.e., formyl methionine-containing peptide and the Ca2+ ionophore A23187). In contrast, the non-steroidal anti-inflammatory drugs (indomethacin, meclofenamic acid and aspirin), which only block the cyclo-oxygenase pathway of AA metabolism, had little effect on enzyme release from PMNs induced by the same stimuli. 5,8,11-Eicosatriynoic acid (ETI), a selective inhibitor of the lipoxygenase pathway of AA metabolism, caused a dose-dependent inhibition of lysosomal enzyme release elicited by Zx, f-met peptide, and A23187. p-Bromophenacyl bromide (BPB), which inhibits the phospholipase A2 (PLA2) activity in several tissues, was found to cause a dose-dependent inhibition of lysosomal enzyme release induced by the same immunological and non-immunological stimuli. The inhibitory effect of BPB on enzyme release was irreversible and extremely rapid. It appears that activation of PLA2 and the products of the AA metabolism, generated via a lipoxygenase pathway, play an essential role in the biochemical control of human PMNs activation and secretion.
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PMID:Possible role of arachidonic acid and of phospholipase A2 in the control of lysosomal enzyme release from human polymorphonuclear leukocytes. 664 91

The effect of indomethacin on bone resorption was studied in an organ culture system, using calvarial bones from 6--7-day-old mice. It was found that indomethacin inhibited spontaneous bone resorption, as estimated by decreased release of 45Ca, Ca2+ and Pi. Indomethacin reduced the release of beta-glucuronidase, beta-galactosidase and beta-N-acetylglucosaminidase, diminished glucose consumption and lactate production, but showed no effect on the release of lactate dehydrogenase. No inhibitory effect of indomethacin on the release of 45Ca stimulated by parathyroid hormone, prostaglandin E2 or 1 alpha(OH)D3 could be registered. 5,8,11,14-eicosatetraynoic acid, an inhibitor of both cyclo- and lipoxygenase pathway of arachidonate metabolism, reduced the spontaneous release of 45Ca, whereas the selective lipoxygenase inhibitor 5,8,11-eicosatriynoic acid was without effect. The results presented indicate that indomethacin may have an inhibitory effect upon the osteoclasts, probably by decreased metabolism of arachidonic acid via the cyclo-oxygenase pathway. A possible relationship between this finding and the pathogenesis of rapid destruction of articular bone in osteoarthritic patients treated with indomethacin is discussed.
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PMID:Indomethacin inhibits bone resorption and lysosomal enzyme release from bone in organ culture. 745 22

Protoplasts were isolated from lentil (Lens culinaris) roots and their suitability as a transient expression system was investigated. After transfecting the protoplasts with the beta-glucuronidase (GUS) gene by either electroporation or polyethylene glycol (PEG), the specific activity of the reporter enzyme and the cell viability were determined. Electroporation was more effective than PEG treatment as transfection procedure and its efficiency was affected by the plasmid length. The feasibility of electro-transferring at the same time (coelectroporation) inhibitory anti-lipoxygenase monoclonal antibodies and the GUS-carrying plasmid pBI 221 was investigated as well. The amount of transferred immunoglobulins was quantitated by ELISA and the inhibitory ability of monoclonal antibodies on the intracellular target enzyme was determined. Evidence is presented for the successful coelectroporation of immunoglobulins and plasmid DNA into lentil protoplasts, the two types of macromolecules acting independently of each other in the recipient cells.
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PMID:Lentil root protoplasts: a transient expression system suitable for coelectroporation of monoclonal antibodies and plasmid molecules. 782 2

Part of the 5'-flanking sequence of a pea (Pisum sativum) lipoxygenase (LOX) gene was cloned, after amplification from genomic DNA by inverse polymerase chain reaction. Translational and transcriptional fusions of 818 bp of the 5'-flanking region and its deletion derivatives (-513 and -356) were made to a beta-glucuronidase (GUS)-coding sequence and introduced into tobacco. Analysis of T1 transformants showed that the 818 bp 5'-flanking sequence drove GUS expression in seeds that was temporally regulated in a fashion similar to the accumulation of LOX mRNA in developing pea seeds. Contrary to expectations, however, expression of the 818 bp promoter-GUS fusion was not seed-specific; GUS activity was highest in leaves and also present in stems and, to a lesser extent, roots. Deletion analyses identified the region between -818 and -513 as essential for high-level, temporally regulated expression in seeds and also indicated that the sequence between -513 and -356 plays a negative role in leaf/stem, but not seed, expression. Comparison of translational and transcriptional fusions indicated that the LOX initiation codon was used more efficiently than the GUS initiation codon by the tobacco leaf translational apparatus.
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PMID:Isolation of a pea (Pisum sativum) seed lipoxygenase promoter by inverse polymerase chain reaction and characterization of its expression in transgenic tobacco. 794 73

The mode of action of the new leukotriene synthesis inhibitor BAY X1005 ((R)-2-[4-(quinolin-2-yl-methoxy)phenyl]-2-cyclopentyl acetic acid) and structurally-related quinoline derivatives is reflected by the binding to a high-affinity binding site presumably identical to FLAP (five lipoxygenase activating protein). In addition to FLAP, we have identified a second BAY X1005 (low-affinity) binding site localized in the granule fraction of human PMNL (polymorphonuclear leukocytes). Based on the hypothesis that the corresponding target protein might be involved in the regulation of granule release, the influence of the leukotriene synthesis inhibitors BAY X1005 and MK-886 and the direct 5-LOX (5-lipoxygenase, EC 1.13.11.34) inhibitor A-64077 on the A23187- and fMLP (N-formyl-methionyl-leucyl-phenylalanine)-stimulated release of beta-glucuronidase (as a marker for azurophil granules) and vitamin B12-binding protein (as a marker for specific granules) was investigated. In contrast to MK-886, neither BAY X1005 nor A-64077 significantly affected fMLP-stimulated granule release. This was also true for the A23187-stimulated release of specific granules; however, under the same conditions the A23187-stimulated release of azurophil granules was almost totally inhibited by all three compounds. No obvious relationship between the corresponding IC50 values and the ability of these compounds to compete for BAY X1005 binding at the low-affinity binding site existed. Instead, by extending these studies to additional inhibitors, a correlation between the IC50 values for inhibition of A23187-stimulated (i) beta-glucuronidase release and (ii) LTB4 (leukotriene B4) synthesis was found (r = 0.969, N = 7). This relationship was independent of the mode of action of the compounds, namely direct 5-LOX inhibition or indirect 5-LOX inhibition mediated via binding to FLAP. These results suggest that 5-LOX metabolites may be involved in A23187-stimulated azurophil granule release. Of the two main biologically active 5-LOX metabolites synthesized under these conditions (LTB4 and 5-hydroxyeicosatetraenoic acid), only LTB4 stimulated beta-glucuronidase release to nearly the same extent as A23187. In addition, this metabolite significantly enhanced A23187-stimulated beta-glucuronidase release, but only at A23187 concentrations (> or = 0.25 mumol/L) which by themselves were not sufficient to trigger LTB4 formation. Moreover, the inhibition of A23187-stimulated beta-glucuronidase release by BAY X1005 or A-64077 was totally reversed by the addition of LTB4.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Ca2+ ionophore A23187-stimulated secretion of azurophil granules in human polymorphonuclear leukocytes is largely mediated by endogenously formed leukotriene B4. 804 28

Human neutrophils were activated by the bacterial chemotactic peptide N-formylmethionyl-leucyl-phenylalanine (fMLP) to produce superoxide (O2-) and to release the primary granule enzyme beta-glucuronidase and the predominantly secondary granule enzyme lysozyme. Pretreatment with granulocyte-macrophage colony-stimulating factor (GM-CSF) increased the secretion of all three substances upon addition of fMLP. The augmentation by GM-CSF was significantly attenuated by the 5-lipoxygenase inhibitor AA861 and by the guanylate cyclase inhibitor LY83583. The secretion induced by fMLP alone was much less affected by either of the two inhibitors. AA861 inhibited leukotriene B4 production in neutrophils primed with GM-CSF and stimulated with fMLP, and LY83583 inhibited GM-CSF-evoked increases of 3',5'-guanosine monophosphate. The data suggest that activation of lipoxygenase and guanylate cyclase is not critical to the fMLP stimulation pathway, but they may be important components of the pathway by which GM-CSF augments neutrophil responses to fMLP. However, AA861 and LY83583 may have important actions in addition to inhibition of 5-lipoxygenase and guanylate cyclase.
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PMID:Effects of inhibition of lipoxygenase and guanylate cyclase on human neutrophil responses to formyl peptide and granulocyte-macrophage colony-stimulating factor. 810 55

Arachidonate (1-300 microM) mobilized Ca2+ ions from an intracellular store and stimulated the entry of Ca2+ ions from the extracellular fluid in undifferentiated HL-60 cells that had been loaded with Fura-2. The integrated response was biphasic in form: arachidonate liberated Ca2+ ions from the intracellular store first, resulting in a transient increase in cytosolic free Ca2+ concentration ([Ca2+]i). Ca2+ entry from the extracellular fluid was not evident for a further 1-2 min. At baseline, [Ca2+]i was 48.1 +/- 14.0 nM (SEM, n = 5). Upon addition of arachidonate (100 microM), [Ca2+]i rose to a transient peak level of 217 +/- 38.6 nM (SEM, n = 5) and a later plateau level of 427 +/- 118 nM (SEM, n = 5). Removal of added Ca2+ ions from the extracellular fluid in the presence of EGTA (1.0 mM) had no effect on the initial transient response but abolished the second phase of the response. In HL-60 cells that had been loaded with BAPTA/AM, the initial transient phase of the response was abolished but the elevation in [Ca2+]i due to Ca2+ entry from the extracellular fluid was unaffected. Undifferentiated HL-60 cells also responded to arachidonate (100 microM) with an increase in the release of the lysosomal enzyme beta-glucuronidase. Arachidonate-induced beta-glucuronidase release from BAPTA-loaded cells or in control cells exposed to Ca(2+)-free solutions was inhibited by about 50%. In BAPTA-loaded cells that were incubated with Ca(2+)-free solutions, arachidonate-induced beta-glucuronidase release was inhibited by about 90%. Leukotriene B4 failed to elevate [Ca2+]i in the concentration range 0.01-1 microM and failed to activate beta-glucuronidase release in concentrations up to 10 microM. Furthermore, the cyclo-oxygenase/lipoxygenase inhibitor ETYA (100 microM) was without effect on secretion. Consistent with this finding, we found that a large number of unsaturated fatty acids could reproduce the effect of arachidonate on [Ca2+]i and beta-glucuronidase release. Fatty acids belonging to the omega-3, omega-6 and omega-7 unsaturated fatty acid families were effective in elevating [Ca2+]i and stimulating beta-glucuronidase release. However, three unsaturated fatty acids, all belonging to the omega-9 fatty acid family, were ineffective.
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PMID:Arachidonate and other fatty acids mobilize Ca2+ ions and stimulate beta-glucuronidase release in a Ca(2+)-dependent fashion from undifferentiated HL-60 cells. 852 54

A number of ring and chain substituted aminothiazole derivatives with strong anti-inflammatory activity were studied for their antiproteolytic and oxygen radical scavenging properties. Their interactions with the stable free radical 1,1-diphenyl-2-picrylhydrazyl was determined. Their inhibition of the soybean 12-lipoxygenase and beta-glucuronidase enzymes was evaluated. They scavenged superoxide anion and inhibited proteolysis to a non appreciable extent, whereas no activity on beta-glucuronidase and lipoxygenase was found. Their reducing ability was found to be low. Good correlation was obtained between the anti-inflammatory activity and clog P (theoretically calculated lipophilicity) and between anti-inflammatory activity and proteolytic inhibition. RM values were also determined.
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PMID:In vitro studies of some 2,4-disubstituted thiazolyl-aminoketones with anti-inflammatory activity. Correlation with lipophilicity and structural characteristics. 900 87

Two lipoxygenase (LOX) genes (tomloxA and tomloxB) are expressed in ripening tomato fruit, and tomloxA is also expressed in germinating seedlings. The 5'-upstream regions of these genes were isolated to study the regulatory elements involved in coordinating tomlox gene expression. Sequence analysis of the promoters did not reveal any previously characterized regulatory elements except for TATA and CAAT boxes. However, the sequence motif GATAcAnnAAtnTGATG was found in both promoters. Chimeric gene fusions of each tomlox promoter with the beta-glucuronidase reporter gene (gus) were introduced into tobacco and tomato plants via Agrobacterium-mediated transformation. GUS activity in tomloxA-gus plants during seed germination peaked at day 5 and was enhanced by methyl jasmonate (MeJa) treatment. No GUS activity was detected in tomloxB-gus seedlings. Neither wounding nor abscisic acid (ABA) treatment of transgenic seedlings modified the activity of either promoter. During fruit development, GUS expression in tomloxA-gus tobacco fruit increased 5 days after anthesis (DAA) and peaked at 20 DAA. In tomloxB-gus tobacco fruit, GUS activity increased at 10 DAA and peaked at 20 DAA. In transgenic tomato fruit, tomloxA-gus expression was localized to the outer pericarp during fruit ripening, while tomloxB-gus expression was localized in the outer pericarp and columella. These data demonstrate that the promoter regions used in these experiments contain cis-acting regulatory elements required for proper regulation of tomlox expression during development and for MeJa-responsiveness.
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PMID:Developmental regulation of two tomato lipoxygenase promoters in transgenic tobacco and tomato. 910 7

Jasmonates induce plant-defence responses and act to regulate defence-related genes including positive feedback of the lipoxygenase 2 (LOX2) gene involved in jasmonate synthesis. To identify jasmonate-signalling mutants, we used a fusion genetic strategy in which the firefly luciferase (FLUC) and Escherichia coli beta-glucuronidase (GUS) reporters were expressed under control of the jasmonate-responsive LOX2 promoter. Spatial and temporal patterns of reporter expression were determined initially, and revealed that JA-responsive expression from the LOX2 promoter required de novo protein synthesis. Reporter activity was also induced by the protein kinase inhibitor staurosporine and antagonized by the protein phosphatase inhibitor okadaic acid. FLUC bio-imaging, RNA gel-blot analysis and progeny analyses identified three recessive mutants that underexpress the FLUC reporter, designated jue1, 2 and 3, as well as two recessive mutants, designated joe1 and 2, that overexpress the reporter. Genetic analysis indicated that reporter overexpression in the joe mutants requires COI. joe1 responded to MeJA with increased anthocyanin accumulation, while joe2 responded with decreased root growth inhibition. In addition, reporter induction and endogenous LOX2 expression by staurosporine was absent in joe2.
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PMID:Fusion genetic analysis of jasmonate-signalling mutants in Arabidopsis. 1187 72


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