Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.31 (beta-glucuronidase)
 7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In continuation of our previous studies, which demonstrated a decreased glutathione peroxidase (GSH-Px) activity of erythrocytes from multiple sclerosis (MS) patients the activity of some enzymes regulating the peroxide level (GSH-PX and glutathione reductase (GSSG-Rd)) in leucocytes and erythrocytes respectively, the selenium level of whole blood and the beta-glucuronidase activity of serum (marker of lysosomal membrane damage) were assayed in this group of patients. GSH-Px activity in lymphocytes and granulocytes from MS patients was significantly (2 alpha smaller than or equal to 0.01) decreased by 35-50%. Erythrocyte glutathione reductase activity was only insignificantly decreased in MS patients. Erythrocyte GSH-Px : GSSG-Rd ratio was 11.0 for the control group, but 8.0 for the MS group. The selenium content of whole blood and serum from Danish MS patients was normal. The selenium level in erythrocytes from Danish MS patients was however higher than the selenium level in erythrocytes from controls.
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PMID:Leucocyte glutathione peroxidase activity and selenium level in multiple sclerosis. 742 Jan 26

The Escherichia coli beta-glucuronidase gene uidA was linked to a region of the Methanococcus voltae genome containing the putative promoter of a gene for a DNA-binding protein and introduced into the M. voltae chromosome. It was found that the enzyme was expressed in the cells in easily measurable amounts. The reporter gene was then placed under the control of the intergenic region found between two divergently transcribed gene groups encoding selenium-free hydrogenases, which are measurably transcribed only after selenium depletion. This region is supposed not only to contain the divergent promoters governing the transcription of the hydrogenase genes but also cis regulatory elements necessary for the negative transcriptional regulation in which selenium is involved. It was shown that the intergenic region functioned as a promoter region for the reporter gene in either orientation. The additional finding that beta-glucuronidase expression was dependent on selenium depletion localizes the cis regulatory elements to the intergenic region between the two hydrogenase operons.
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PMID:Use of the Escherichia coli uidA gene as a reporter in Methanococcus voltae for the analysis of the regulatory function of the intergenic region between the operons encoding selenium-free hydrogenases. 765 45

Mouse colon adenocarcinoma Co38 is widely used as a screening model for human colon tumors. To understand better the influence of tumor size on the main drug-metabolizing enzyme systems, we tested 15 mouse Co38 tumors at different sizes. The average weight was 917 +/- 444 mg (range, 300-1,400 mg). Cytochromes P-450 (1A1/1A2, 2B1/B2, 2C8-10, 2E1, 3A4), epoxide hydrolase (EH), and glutathione-S-transferases (GST-alpha, -mu, and -pi) were assayed by immunoblotting. The activities of the following enzymes or cofactors were determined by spectrophotometric or fluorometric assays: 1-chloro-2,4-dinitrobenzene-GST (CDNB-GST), selenium-independent glutathione peroxidase (GPX), 3,4-dichloronitrobenzene-GST (DCNB-GST), ethacrynic acid-GST (EA-GST), total glutathione (GSH), uridine diphosphate-glucuronosyltransferase (UDP-GT), beta-glucuronidase (beta G), sulfotransferase (ST), and sulfatase (S). Our results showed the absence of all probed P-450s and EH in Co38 tumors. No relationship was found between the Co38 tumor weights and GPX, GST-alpha, and EA-GST (regression analysis). However, a significant correlation was found between the tumor weights and all other enzymes investigated. For certain enzymes or cofactors, a linear decrease (P < 0.05) was observed as a function of tumor weight (CDNB-GST, DCNB-GST, GST-mu, GST-pi, GSH, and beta G). Other enzymatic activities (UDP-GT, S, and ST) were found to decrease in medium-size tumors and to increase in large tumors (P < 0.05; quadratic correlation). These data demonstrate that the expression of many drug-metabolizing enzyme systems is altered during tumor growth and suggest that tumoral response to chemotherapy could be altered as a function of tumor size.
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PMID:Influence of tumor size on the main drug-metabolizing enzyme systems in mouse colon adenocarcinoma Co38. 792 60

Since drug-metabolizing enzymes may influence the toxic response of tissues or organs to drugs, we studied their expression in human and colon tumor tissues, in an attempt to find new targets for chemotherapy and also to explain the intrinsic drug-insensitivity of most colon tumors to anticancer drugs. In the present work, we compared human colorectal tumors and peritumoral tissues to a mouse colorectal tumor (Co38) and normal murine colon with regard to their main drug-metabolizing enzyme systems. We investigated cytochromes P-450 (1A1/1A2, 2B1/B2, 2C, 2E1, 3A) and epoxide hydrolase (EH) by immunoblotting. Total glutathione (GSH) and the activities of the following enzymes: total GST, selenium-independent glutathione peroxidase (GPX), 1,2-dichloro-4-nitrobenzene-GST (DCNB-GST), ethacrynic acid-GST (EA-GST), UDP-glucuronosyltransferase 1 (UDPGT), beta-glucuronidase (beta G), sulfotransferase (ST) and sulfatase (S) were investigated by fluorometric and spectrophotometric assays. Results obtained by immunoblotting showed that mouse colon tumor Co38 did not express any of the probed cytochromes P-450, whereas human tumors showed the presence of cytochrome P-450 3A. EH was not expressed in either mouse colon tumor Co38 or normal mouse colon, whereas it was expressed in human peritumoral and tumoral colon tissues at similar levels. GPX and EA-GST were detected in all tumoral and non tumoral tissues of both species. DCNB-GST was expressed in all murine tissues investigated, but was not found in human tissues. For human peritumoral and tumoral colorectal tissues there was no significant difference between GST isoenzymes levels, whereas mouse colon tumor Co38 had a lower expression of DCNB-GST and EA-GST compared to normal mouse colon. No significant difference was observed between human tumors and peritumoral tissues for total GST, UDPGT1, beta G, ST and S activities. For murine colon tissues, the conjugation pathways (total GST, UDPGT1 and ST) were lower in Co38, whereas the opposite was observed for the hydrolytic enzymes (beta G and S). In conclusion, despite similarities between human and murine colon tumors, mouse colon tumor Co38 appears different from human colon tumors for many drug-metabolizing enzyme systems. These interspecies differences may have implications with regard to drug screening methodologies and preclinical evaluation of candidate anticancer drugs useful in the chemotherapy of human colorectal tumors.
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PMID:[Screening of principal enzymes involved in the metabolism of anticancer drugs in human and murine colonic tumors]. 817 93

Ovalbumin-sensitized (50 mg/kg, i.p.) male Hartley-guinea-pigs (550-610 g; n = 6) were treated 14 days later intratracheally with saline, cadmium (Cd 0.3 mg), selenium (Se 0.3 mg or 0.06 mg) or Se (0.06 mg) with Cd (0.3 mg). After 24 h, baseline dynamic-lung-compliance (Cdynl) and pulmonary-resistance (Rp), and percent change after ovalbumin-aerosol-challenge (10 mg/ml, 60 s) were assessed. Cadmium or Se (0.3 mg), Se (0.06 mg) and/or Cd (0.3 mg) decreased Cdynl (P < 0.05). Selenium (0.3 mg) increased Rp (P < 0.05). Ovalbumin-challenge decreased Cdynl and increased Rp in all groups. Analysis of bronchoalveolar-lavage-fluid (BALF) displayed increased activities of lactate-dehydrogenase (LDH), beta-glucuronidase (beta-G), alkaline-phosphatase (AP), and protein due to 0.3 mg Se, 0.3 mg Cd alone or with 0.06 mg Se (P < 0.05). Findings indicated that, 0.3 mg Se is more detrimental than 0.3 mg Cd to lung-dynamics despite a modest protection by 0.06 mg Se against Cd illustrated by an ameliorated Cdynl and lower protein in BALF.
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PMID:Selenium and cadmium induced pulmonary functional impairment and cytotoxicity. 906 78

We developed a general method for the site-specific deletion of gene sequences to obtain new selectable markers in the archaeon Methanococcus voltae. Using a deletion in the hisA gene, a vector was integrated into the chromosome by homologous recombination, thereby reconstituting histidine prototrophy. The vector contained the beta-glucuronidase gene uidA of Escherichia coli as a reporter under the control of an M. voltae promoter that normally drives the expression of a selenium-free [NiFe]-hydrogenase after selenium deprivation. This construct has allowed us to check whether the selenium supply was sufficiently low to induce the transcription of the genes encoding the selenium-free hydrogenases. We tried to introduce a chromosomal deletion of the vhuU gene of the archaeon M. voltae by gene replacement and by keeping the cells under selenium deprivation. The gene vhuU encodes the very small, selenocysteine-containing subunit that is part of the primary reaction center of the Vhu hydrogenase. All transformants bearing the deletion also contained the vhuU wild-type gene. Therefore, the vhuU gene appears to be essential for the cell even under conditions that lead to the induction of the selenium-free homologue Vhc of the Vhu hydrogenase.
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PMID:The vhuU gene encoding a small subunit of a selenium-containing [NiFe]-hydrogenase in Methanococcus voltae appears to be essential for the cell. 979 85

The effect of poisoning doses of selenium on serum matrix-degrading enzymes activity was investigated in rats intoxicated with selenium. Fifteen animals were receiving orally sodium selenite in a daily dose of 300 microg/kg body weight. Intoxication with selenium was carried out for 10 weeks. The present study revealed significant increase in activities of enzymes involved in the connective tissue matrix metabolism i.e. beta-glucuronidase, N-acetyl-beta-glucosaminidase, elastase and collagen peptidase. There was no change in the cathepsin activity. The relative enzyme activities calculated over protein level resulted in higher values than those found in direct measurements. Serum enzyme activity was increased most for elastase (about 31%) and N-acetyl-beta-glucosaminidase (about 33%) based on activity per gram of protein. The current data indicate that lysosomes are target organelles for selenium toxicity. Generalized increase in lysosomal enzymes activity contributes to the altered metabolism of the connective tissue in selenium-intoxicated animals. The mechanisms that lead to the increase of lysosomal enzymes activity in rats receiving poisoning doses of selenium could be related to biochemical disturbances caused by selenium toxicity.
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PMID:Serum matrix-degrading enzymes in rats intoxicated with selenium. 1124 90

The J774.1 macrophage cell line was used as a tool to investigate the influence of selenium on macrophage function. In vitro selenium supplementation enhanced phagocytosis, degranulation by the release of beta-glucuronidase after N-formyl-methionyl-leucyl-phenylalanine (FMLP) or cytochalasin B, and the production of superoxide anion after phorbol myristate acetate stimulation of these cells, while the release of nitric oxide was not affected by the selenium status. Selenium supplementation enhanced significantly (p < 0.05) the release of tumor necrosis factor (5-fold), interleukin-1 (3-fold) and interleukin-6 (2.5-fold) after 10 microg/ml lipopolysaccharide stimulation compared to selenium-deficient cells.
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PMID:The effect of selenium on immune functions of J774.1 cells. 1296 5


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