Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have purified beta-galactosidase and beta-glucuronidase from macrophages of thioglycollate-treated mice using concanavalin A chromatography and immunoprecipitation. The apparent molecular weight of the beta-galactosidase subunit, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, changed during a long term pulse-chase experiment. Following a 1-h pulse with [3H]leucine, radiolabel was present exclusively in an Mr = 82,000 form. However, after a 3-h chase in medium containing unlabeled leucine, most label migrated at Mr = 63,000, and at 24 h, all label was in the Mr = 63,000 form. Electrophoresis of peptides produced by cyanogen bromide cleavage of immunoprecipitates demonstrated structural similarities between precursor and mature forms. A mutation in the mouse, which is known to depress the rate of synthesis of beta-galactosidase in many cell types, proportionately decreased incorporation of [3H]leucine into both the Mr = 82,000 and 63,000 forms. Therefore, by kinetic, structural, and genetic evidence, the large molecular weight beta-galactosidase is a precursor of mature macrophage enzyme. No precursor of the Mr = 75,000 subunit of beta-glucuronidase was detected.
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PMID:Biosynthesis of two lysosomal enzymes in macrophages. Evidence for a precursor of beta-galactosidase. 11 27

It was possible to define the effects of trehalose dimycolate (TDM), a glycolipid extracted from Mycobacterium tuberculosis, on mouse peritoneal macrophages more precisely using endotoxin-free culture conditions. TDM-elicited macrophages, when assayed in vitro in the absence of endotoxin, were unable to limit tumor growth; however, after a short treatment (4 h) with low doses of lipopolysaccharide (LPS; 1-10 ng/ml), they exhibited a strong cytostatic capacity against P815 mastocytoma cells. Thus, TDM injected in vivo did not activate macrophages fully but it primed them to respond in vitro to low doses of LPS, which provided the final stimulus for activation to antitumor competence. Macrophages elicited by an injection of killed group C Streptococci were also in a primed state; in contrast, thioglycollate-elicited macrophages were in a nonreceptive state. Besides LPS, concanavalin A (5 micrograms/ml), MDP (0.2-1 microgram/ml) and the ionophore A23187 (5 microM) can deliver the activation signal to TDM-primed macrophages. Primed macrophages were found to express several biochemical markers previously described as specific for activated macrophages (low levels of alkaline phosphodiesterase and beta-galactosidase, for example) and, although they were not cytotoxic for tumor cells, they had the capacity to release large amounts of H2O2. However, when pulsed by LPS or MDP, primed macrophages responded by further modifications in their metabolism: the rate of glucose consumption and the labeling of glycoproteins by D-[2-3H]mannose were greatly increased and the secretion of a polypeptide of 22 kDa was enhanced. The activation-associated biochemical markers are thus acquired in two steps. The ability to produce activated oxygen species is expressed earlier than the antitumoral activity.
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PMID:Macrophage activation by trehalose dimycolate requirement for an expression signal in vitro for antitumoral activity; biochemical markers distinguishing primed and fully activated macrophages. 300 1

Pure cultures of three types of mononuclear phagocytes-mouse peritoneal macrophages, unstimulated or after thioglycollate stimulation, and human monocytes-synthesize and secrete large amounts of lysozyme in vitro. The macrophage lysozyme is indistinguishable from authentic lysozyme in its ability to lyse M. lysodeikticus, inhibition by specific antisera, a similar size of 14,000 and cationic charge. Lysozyme secretion in culture is characterized by a large net increase in total lysozyme, 4-20-fold in 3 h, 75-95% of which is in the medium, and its continued extracellular accumulation over at least 2 wk in culture. Lysozyme is the major (14)C-labeled protein secreted into the medium by both unstimulated and thioglycollate-stimulated macrophages and the 0.75-1 microg produced per 1 x 10(6) cells/day represents 0.5-2.5% of the total cell protein. Lysozyme is a cell-specific marker for mononuclear phagocytes and the PMN, which contains preformed enzyme, since it is absent in lymphoid cells and a variety of fibroblast and epithelioid cell lines. Lysozyme production is also a useful measure of mononuclear phagocyte cell number. The rate of lysozyme production and secretion is remarkably constant for all cell types under a variety of culture conditions. Production by the mouse macrophage increases threefold on the 2nd day in culture and then remains linear with time. Production is optimal at a relatively low serum concentration, but can be maintained, in the absence of serum, in lactalbumin hydrolysate or, at a reduced level in basal media. The production and secretion of lysozyme are independent of the production of macrophage acid hydrolases. Net increase and secretion of lysozyme occur under conditions where acid hydrolases like N-acetyl beta-glucosaminidase, beta-glucuronidase, beta-galactosidase, and cathepsin D are neither accumulated nor secreted. Massive phagocytosis of latex particles has no effect on lysozyme production and secretion. Lysozyme production can be rapidly inhibited by treatment with cycloheximide (0.4 microg/ml) whereas inhibition of its production by colchicine (10(-6) M) occurs only after a lag period of more than 8 h, and is probably due to a secondary effect. These results show that mouse macrophages provide a simple in vitro system to measure lysozyme secretion and its control. These studies also indicate the possible importance of mononuclear phagocytes in the secretion of a variety of biologically active products and in the modification of their environment.
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PMID:In vitro synthesis and secretion of lysozyme by mononuclear phagocytes. 482 44

Peritoneal exudate cells of mice were studied up to 4 days after i.p. injection of thioglycollate broth medium by means of conventional enzyme determinations and quantitative histochemical measurements of individual cells. Cells from the peritoneal cavity were either investigated immediately after harvesting or after culturing periods of up to six days for enzymic activities of aminopeptidase, esterase, lactate dehydrogenase and beta-galactosidase. A fairly good correlation exists between biochemical determinations of aminopeptidase and esterase activity and the mean of histochemical data. Following a sharp increase in the number of cells after stimulation, aminopeptidase, esterase and lactate dehydrogenase activities per cell were found to be increased. Moreover, the cells taken three or five days after simulation synthesized large amounts of aminopeptidase and esterase as shown by culturing experiments. This capacity of the cells was subsequently lost in cells harvested seven days after stimulation but beta-galactosidase increased and lactae dehydrogenase was more readily released into culture supernatants. The increase in aminopeptidase and esterase was dependent on protein synthesis since it was abolished by cycloheximide. Thioglycollate broth medium provokes immigration of cells into the peritoneal cavity where cells apparently differentiate by increasing their aminopeptidase and esterase concentrations, and by raising their intracellular catabolism rates, which leads eventually to the decay of the cells. The different enzymic phenotypes and the large heterogeneity at any time point after stimulation presumably also reflect different functional properties during the inflammatory process.
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PMID:Stimulated murine peritoneal macrophages in suspension and cell culture: enzyme determinations by biochemical and histochemical means. 680 41

Resident, elicited, and activated mouse peritoneal macrophages exhibit a differential expression of the activity of the enzyme beta-galactosidase; freshly harvested resident macrophages express a remarkably high activity whereas the latter two populations are almost void of enzymic activity. During in vitro cultivation there is an enhancement in the level of the enzyme in the three populations, and a significant proportion of both thioglycollate-elicited and Corynebacterium parvum-activated macrophages acquire beta-galactosidase activity. Cells within in vitro differentiated bone marrow-derived mononuclear phagocyte colonies are heterogeneous with respect to expression of beta-galactosidase activity. The percentage of cells expressing medium to intense enzymic activity is augmented with time in culture. Essentially the same pattern is observed in colonies differentiated from bone marrows of mice bearing acute or chronic inflammation. Freshly isolated human peripheral blood monocytes are essentially void of detectable beta-galactosidase activity. Eighty to ninety percent of the monocytes acquire medium to intense activity during a 7-day cultivation period. The data support the suggestion that beta-galactosidase expression in mononuclear phagocytes is a correlate of their maturational stage both in vivo and in vitro and does not reflect the state of elicitation or activation of these cells.
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PMID:Beta-galactosidase--an indicator of the maturational stage of mouse and human mononuclear phagocytes. 681 41

The mechanisms that regulate the selective infiltration of eosinophils in certain allergic diseases are still poorly understood. The CC chemokine eotaxin is a potent chemoattractant, highly specific for eosinophils. Recent studies have implicated that eotaxin plays an important role in the recruitment of eosinophils in different inflammation processes. A number of other chemokines, cytokines, and chemoattractants also have chemotactic activities for eosinophils and some of them present high selectivity for eosinophils. To further study the role of eotaxin in inflammation, we generated mutant mice with the eotaxin gene disrupted and replaced by the Escherichia coli beta-galactosidase gene. These mice developed normally and had no histologic or hematopoietic abnormalities. Furthermore, our studies showed that the lack of eotaxin did not affect the recruitment of eosinophils in the inflammation models induced by Sephadex beads and thioglycollate, as well as in an experimental lung eosinophilia model induced by ovalbumin aerosol challenge, even at the onset of the inflammatory response. The replacement of the eotaxin gene by the beta-galactosidase gene provided a useful marker to monitor the activity of the eotaxin promoter under normal conditions and after antigen challenges. Immunohistochemical staining suggested that endothelial cells were the major sources of eotaxin expression.
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PMID:Antigen-induced eosinophilic lung inflammation develops in mice deficient in chemokine eotaxin. 980 85

Three major inhibitors of the NF-kappaB/Rel family of transcription factors, IkappaBalpha, IkappaBbeta, and IkappaBepsilon, have been described. To examine the in vivo role of the most recently discovered member of the IkappaB family, IkappaBepsilon, we generated a null allele of the murine IkappaBepsilon gene by replacement of all coding sequences with nlslacZ. Unlike IkappaBalpha nullizygous mice, mice lacking IkappaBepsilon are viable, fertile, and indistinguishable from wild-type animals in appearance and histology. Analysis of beta-galactosidase expression pattern revealed that IkappaBepsilon is mainly expressed in T cells in the thymus, spleen, and lymph nodes. Flow cytometric analysis of immune cell populations from the bone marrow, thymus, spleen, and lymph nodes did not show any specific differences between the wild-type and the mutant mice, with the exception of a reproducible 50% reduction of the CD44-CD25+ T cell subspecies. The IkappaBepsilon-null mice present constitutive up-regulation of IgM and IgG1 Ig isotypes together with a further increased synthesis of these two isotypes after immunization against T cell-dependent or independent Ags. The failure of observable augmentation of constitutive nuclear NF-kappaB/Rel-binding activity is probably due to compensatory mechanisms involving IkappaBalpha and IkappaBbeta, which are up-regulated in several organs. RNase-mapping analysis indicated that IL-1alpha, IL-1beta, IL-1Ra, and IL-6 mRNA levels are constitutively elevated in thioglycolate-elicited IkappaBepsilon-null macrophages in contrast to GM-CSF, G-CSF, and IFN-gamma, which remain undetectable.
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PMID:IkappaBepsilon-deficient mice: reduction of one T cell precursor subspecies and enhanced Ig isotype switching and cytokine synthesis. 1057 Feb 87