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

---

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

Collagenase perfusion of the liver followed by pronase treatment of the cell suspension thus obtained gave a quantitative recovery of viable nonparenchymal liver cells (NPC). From these NPC, Kupffer (K) cells can be purified by attachment to tissue culture dishes. Tail vein injection of carbon 1-2 h before liver perfusion permitted stepwise calculation as well as visualization of carbon-containing K cells. When these K cells have been put into tissue culture medium with serum and incubated overnight, they exhibit typical macrophage characteristics. Phase-contrast and transmission electron microscopy showed typical macrophage morphology and scanning electron microscopy revealed well-spread cells with cytoplasmic projections and ruffled membranes. Endocytosis studies using radioactive colloidal gold and inert latex particles also indicated that these cells are highly active in pinocytosis and phagocytosis. Further characterization of K cells is the identification of Fc receptor on their membranes. Studies on lysosomal enzymes showed that purified K cells possess higher specific activities in beta-glucuronidase, acid DNase, and cathepsin D than in purified parenchymal cells.
...
PMID:Mass isolation and culture of rat kupffer cells. 109 Jun 96

Chemically induced hypothyroidism changes the functions of rat alveolar macrophages. Treatment of female rats with an anti-thyroid drug, methimazole (1% aqueous solution in drinking water for 6 weeks) significantly (p less than 0.05) reduced the ability of alveolar macrophages (MAM) to phagocytose and kill the yeast, Saccharomyces cerevisiae. Undigested yeasts were observed in phagolysosomes within MAM using transmission electron microscopy. The activities of the lysosomal enzymes, acid phosphatase and beta-glucuronidase, and the Fc receptor binding ability for immunoglobulin G, were lowered in MAM when compared with control macrophages (CAM). MAM also produced less tumor necrosis factor under the stimulation of lipopolysaccharide.
...
PMID:Effect of methimazole-induced hypothyroidism on alveolar macrophages. 167 73

Mouse L cells that possess the cation-independent mannose 6-phosphate (Man 6-P)/insulin-like growth factor (IGF) II receptor change the extent to which they dephosphorylate endocytosed acid hydrolases in response to serum (Einstein, R., and C. A. Gabel. 1989. J. Cell Biol. 109:1037-1046). To investigate the mechanism by which dephosphorylation competence is regulated, the dephosphorylation of individual acid hydrolases was studied in Man 6-P/IGF II receptor-positive and -deficient cell lines. 125I-labeled Man 6-P-containing acid hydrolases were proteolytically processed but remained phosphorylated when endocytosed by receptor-positive L cells maintained in the absence of serum; after the addition of serum, however, the cell-associated hydrolases were dephosphorylated. Individual hydrolases were dephosphorylated at distinct rates and to different extents. In contrast, the same hydrolases were dephosphorylated equally and completely after entry into Man 6-P/IGF II receptor-positive Chinese hamster ovary (CHO) cells. The dephosphorylation competence of Man 6-P/IGF II receptor-deficient mouse J774 cells was more limited. beta-Glucuronidase produced by these cells underwent a limited dephosphorylation in transit to lysosomes such that diphosphorylated oligosaccharides were converted to monophosphorylated species. The overall quantity of phosphorylated oligosaccharides associated with the enzyme, however, did not decrease within the lysosomal compartment. Likewise, beta-glucuronidase was not dephosphorylated when introduced into J774 cells via Fc receptor-mediated endocytosis. The CHO and J774 cell lysosomes, therefore, display opposite extremes with respect to their capacity to dephosphorylate acid hydrolases; within CHO cell lysosomes acid hydrolases are rapidly and efficiently dephosphorylated, but within J774 cell lysosomes the same acid hydrolases remain phosphorylated. This difference in processing indicates that lysosomes themselves exist in a dephosphorylation-competent and -incompetent state. Man 6-P-bearing acid hydrolases endocytosed by the L+ cells in the absence of serum were not distributed uniformly throughout the lysosomal compartment. The change in the dephosphorylation competence of L cells in response to serum suggests, therefore, that these cells contain multiple populations of lysosomes that differ with respect to their content of a mannose 6-phosphatase, and that serum factors affect the distribution of hydrolases between the different compartments.
...
PMID:Cell- and ligand-specific dephosphorylation of acid hydrolases: evidence that the mannose 6-phosphatase is controlled by compartmentalization. 184 1

Balb/c mice bearing a methylcholanthrene-induced fibrosarcoma were used to compare the activation levels of tumor-associated and peritoneal macrophages. Two stages of tumor growth were examined, namely "small" and "large" tumors, with average diameters of 10 and 30 mm, respectively. The activation state, determined by measurement of both phagocytic index and beta-glucuronidase content, was found to be markedly higher in tumor-associated macrophages than in their peritoneal counterparts and it was, in addition, independent of tumor progression. The percentage of tumor-associated macrophages, which were detected on the basis of Fc receptor expression, remained constant in the growing neoplasm, at approximately 23% of total cell population. None of these parameters were affected by inoculation with an immunopotentiating dose of heat-killed Candida albicans which, on the other hand, seemed not to alter the course of the tumor. These data suggest that within the tumor microenvironment macrophages would somehow be maintained at a constant proportion and at a highly activated state, while outside the tumor they would be at a lower activation level. Our results also suggest that TAM would not possess antitumor activity in vivo, although we have found this activity in vitro.
...
PMID:Comparative activation states of tumor-associated and peritoneal macrophages from mice bearing an induced fibrosarcoma. 209 3

We studied beta-glucuronidase release from human monocytes induced with aggregated immunoglobulins of the nine different human classes and subclasses. Release was induced in a time and dose-dependent manner by all aggregated IgG subclasses. Aggregated IgA1 caused a greater beta-glucuronidase release than aggregated IgM, IgD, and IgE, but the difference was not statistically significant. Release of beta-glucuronidase was not phagocytosis dependent since inhibition of phagocytosis by cytochalasin B or dihydrocytochalasin B did not diminish enzyme release. On the contrary, cells incubated with cytochalasin B prior to addition of aggregated IgG released approximately twice as much enzyme compared to untreated controls. Enzyme release induced by latex particles, a non-Fc receptor mechanism, was decreased by cytochalasin B. Monomeric IgG1, IgG2, IgG3, and IgG4 inhibited aggregated IgG1 enzyme release in a dose-dependent manner. The ability of monomeric IgG to inhibit beta-glucuronidase release correlated with previous reports describing the binding affinities of monomeric IgG to monocytes, i.e., IgG2 was relatively ineffective compared to the other subclasses. Monomeric IgA, IgE, and pentameric IgM were unable to diminish IgG-induced enzyme release. The data indicate that normal peripheral blood monocytes express predominantly Fc receptors for IgG and that all four IgG subclasses induce the release of the lysosomal enzyme beta-glucuronidase.
...
PMID:beta-Glucuronidase release from human monocytes induced with aggregated immunoglobulins of different classes. 242 25

Lymphocytes, co-expressing CD4/Leu7 and CD8/Leu7 markers respectively, taken from two patients having large granular lymphocytosis taking an indolent clinical course have been comparatively studied for function as NK cells and T cells. Both large granular lymphocytes (LGLs) were acid phosphatase positive and showed a beta-glucuronidase reaction in their cytoplasmic granules. Studies on case 1 indicated that the CD4/Leu7 lymphocytosis with LGL morphology takes a benign clinical course with mild neutropenia as well as those of CD8/Leu7 LG lymphocytosis. Both CD4/Leu7 and CD8/Leu7 LGLs behave similarly in their lack of NK activity, and manifest decreased IL-2 production in vitro and show a low IL-2 receptor expression unrelated to their T cell phenotype, but behave differently in influencing the immunoglobulin production in vitro and the ADCC activity, depending on their T cell phenotype and on the expression of Fc receptor, respectively. Furthermore, the altered Fc receptors which were undetectable by the Leul 1 antibody but were still effective for ADCC activity might be present in case 2 LGLs.
...
PMID:CD4/Leu7 and CD8/Leu7 large granular lymphocytosis: comparative studies between NK cells and T cells. 251 16

Early steps of receptor-mediated endocytosis appear to require the fusion of endosomes with each other. Recently, these fusion events have been reconstituted in vitro using vesicle preparations from J774 macrophages which have internalized ligands via the mannose receptor (Diaz, R., Mayorga, L., and Stahl, P. (1988) J. Biol. Chem. 263, 6093-6100). The present studies indicate that endosomes first form clusters when incubated under fusogenic conditions. Aggregation state was determined by electron microscopy using vesicles containing ligand-coated colloidal gold of different sizes previously internalized via the mannose receptor. Aggregation required cytosol and ATP. Afterwards, the limiting membranes of the vesicles composing these aggregates undergo multiple fusion and bring about the formation of large diameter vesicles that maintained the same density as endosomes when analyzed by Percoll gradient sedimentation. These large diameter vesicles were no longer fusogenic in the fusion assay. Multiple fusion was determined morphologically by the co-localization of three different size colloidal gold vesicles inside endocytic vesicles and biochemically by the fusion-dependent formation of triple immune complexes between three endocytic ligands internalized by receptor-mediated endocytosis: anti-dinitrophenol mouse IgG and dinitrophenol-derivatized beta-glucuronidase, ligands for the mannose receptor, and aggregated rabbit anti-mouse IgG, a ligand for the macrophage Fc receptor.
...
PMID:In vitro clustering and multiple fusion among macrophage endosomes. 275 8

We have used monospecific antisera to two lysosomal membrane glycoproteins, lgp120 and a similar protein, lgp110, to compare the biosynthesis and intracellular transport of lysosomal membrane components, plasma membrane proteins, and lysosomal enzymes. In J774 cells and NRK cells, newly synthesized lysosomal membrane and plasma membrane proteins (the IgG1/IgG2b Fc receptor or influenza virus hemagglutinin) were transported through the Golgi apparatus (defined by acquisition of resistance to endo-beta-N-acetylglucosaminidase H) with the same kinetics (t1/2 = 11-14 min). In addition, immunoelectron microscopy of normal rat kidney cells showed that lgp120 and vesicular stomatitis virus G-protein were present in the same Golgi cisternae demonstrating that lysosomal and plasma membrane proteins were not sorted either before or during transport through the Golgi apparatus. To define the site at which sorting occurred, we compared the kinetics of transport of lysosomal and plasma membrane proteins and a lysosomal enzyme to their respective destinations. Newly synthesized proteins were detected in dense lysosomes (lgp's and beta-glucuronidase) or on the cell surface (Fc receptor or hemagglutinin) after the same lag period (20-25 min), and accumulated at their final destinations with similar kinetics (t1/2 = 30-45 min), suggesting that these two lgp's are not transported to the plasma membrane before reaching lysosomes. This was further supported by measurements of the transport of membrane-bound endocytic markers from the cell surface to lysosomes, which exhibited additional lag periods of 5-15 min and half-times of 1.5-2 h. The time required for transport of newly synthesized plasma membrane proteins to the cell surface, and for the transport of plasma membrane markers from the cell surface to lysosomes would appear too long to account for the rapid transport of lgp's from the Golgi apparatus to lysosomes. Thus, the observed kinetics suggest that lysosomal membrane proteins are sorted from plasma membrane proteins at a post-Golgi intracellular site, possibly the trans Golgi network, before their delivery to lysosomes.
...
PMID:Kinetics of intracellular transport and sorting of lysosomal membrane and plasma membrane proteins. 282 Oct 12

The Fc receptor mediated reaction, the beta-glucuronidase and the lactic dehydrogenase activities of monocytes and the serum lysozyme level were tested together with the circulating immune complex content of patients with systemic lupus erythematosus. Simultaneously with the increasing FC receptor-mediated reaction and the elevated enzyme activities of patient monocytes, the secretion of lysozyme and the immune complex content of the sera were higher than those of the controls. A positive correlation was demonstrated between the Fc receptor-mediated reaction, the beta-glucuronidase activity, the lysozyme secretion and the immune complex content of the sera. Thus, the monocytes of patients appeared to be activated by the circulating immune complexes.
...
PMID:Signals of monocyte activation in patients with SLE. 683 41

The murine macrophage-like cell line P388D1 has Fc fragment receptors but cannot carry out Fc receptor-mediated phagocytosis. We now find that it gains this ability when exposed to 1.5% dimethyl sulfoxide for 2 days. Binding by Fc receptors and phagocytosis of latex beads are unaffected. Growth eventually slows, and the activities of two lysosomal enzymes--beta-glucuronidase and acid phosphatase--increase, but these increases occur after the induction of Fc receptor-mediated phagocytosis. Cycloheximide sufficient to inhibit protein synthesis inhibits the effect of dimethyl sulfoxide. All changes are reversed when dimethyl sulfoxide is removed. This system may facilitate study of differentiation processes affecting Fc receptor-mediated phagocytosis.
...
PMID:Induction by dimethyl sulfoxide of Fc fragment-mediated phagocytosis in the mouse macrophage-like cell line P388D1. 695 7


1 2 Next >>

---